Rustic Cabin Beef and Buckwheat Casserole

Quick Recipe Version (TL;DR)

• Yield: 6 servings
• Prep Time: 25 minutes
• Cook Time: 1 hour 10 minutes
• Total Time: 1 hour 35 minutes

Quick Ingredients

• 1 1/2 cups (270 g) buckwheat groats (kasha)
• 4 3/4 cups (1.12 L) low-sodium beef broth, divided
• 1 1/2 lb (680 g) beef sirloin or chuck, cut in thin strips
• 2 large yellow onions, thinly sliced
• 1 cup (120 g) sliced cremini mushrooms (optional)
• 3 Tbsp unsalted butter
• 2 Tbsp olive or vegetable oil
• 1/4 cup (30 g) all-purpose flour
• 1 cup (240 ml) whole milk or half-and-half
• 1/3 cup (80 ml) sour cream
• Garlic, thyme, parsley, Worcestershire, Dijon, bay leaf
• Salt, black pepper, smoked paprika

Do This

• 1. Preheat oven to 375°F (190°C). Grease a 9×13-inch (23×33 cm) or 3-quart casserole dish.
• 2. Toast buckwheat in a dry pan, then simmer with 2 3/4 cups broth until just tender; spread in the casserole dish.
• 3. Season and sear beef strips in hot oil until browned; transfer to a plate.
• 4. In the same pan, sauté onions (and mushrooms, if using) until golden and soft; add garlic and herbs.
• 5. Make a roux with butter and flour, whisk in 2 cups broth and milk to form a creamy herb gravy; finish with sour cream, Worcestershire, Dijon, and seasoning.
• 6. Layer onions and beef over buckwheat, pour gravy on top, cover with foil, and bake 25 minutes. Uncover and bake 10–15 minutes more until bubbling. Rest 10 minutes before serving.

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Why You’ll Love This Recipe

• Deeply comforting and hearty, perfect for chilly evenings or a rustic cabin-style dinner.
• Uses budget-friendly cuts of beef and buckwheat for a satisfying, earthy, and wholesome meal.
• Everything bakes in one pan for easy serving and minimal cleanup.
• Makes excellent leftovers and reheats beautifully for next-day lunches.

Grocery List

• Produce: Yellow onions, garlic, fresh thyme (or dried), fresh parsley, cremini mushrooms (optional)
• Dairy: Unsalted butter, whole milk or half-and-half, sour cream
• Pantry: Buckwheat groats (kasha), low-sodium beef broth, olive or vegetable oil, all-purpose flour, Worcestershire sauce, Dijon mustard, smoked paprika, bay leaf, kosher salt, black pepper

Full Ingredients

For the casserole base

• 1 1/2 cups (270 g) buckwheat groats (kasha), preferably toasted
• 2 3/4 cups (650 ml) low-sodium beef broth
• 1/2 tsp kosher salt (for the buckwheat)

For the beef and onions

• 1 1/2 lb (680 g) beef sirloin, flank, or chuck steak, cut into thin strips about 1/2 inch (1.25 cm) wide and 2 inches (5 cm) long
• 1 tsp kosher salt
• 1/2 tsp freshly ground black pepper
• 1/2 tsp garlic powder
• 1 Tbsp all-purpose flour (for lightly dusting the beef)
• 2 Tbsp olive oil or vegetable oil
• 2 large yellow onions, halved and thinly sliced
• 1 cup (120 g) sliced cremini or button mushrooms (optional but delicious)
• 3 cloves garlic, minced
• 1 tsp fresh thyme leaves, minced (or 1/2 tsp dried thyme)

For the creamy herb gravy

• 3 Tbsp unsalted butter
• 1/4 cup (30 g) all-purpose flour
• 2 cups (480 ml) low-sodium beef broth
• 1 cup (240 ml) whole milk or half-and-half
• 1 bay leaf
• 1 tsp fresh thyme leaves, minced (or 1/2 tsp dried thyme)
• 1 Tbsp Worcestershire sauce
• 1 tsp Dijon mustard
• 1/2 tsp smoked paprika
• 1/3 cup (80 ml) sour cream, at room temperature
• 1/2 tsp kosher salt, or to taste
• 1/4 tsp freshly ground black pepper, or to taste

For assembling & serving

• 1–2 Tbsp chopped fresh parsley, for garnish
• Additional black pepper, to finish
• Butter or oil, for greasing the baking dish

Step-by-Step Instructions

Step 1: Preheat and prepare your baking dish

Preheat your oven to 375°F (190°C) with a rack in the center position. Grease a 9×13-inch (23×33 cm) or similarly sized 3-quart casserole dish with a little butter or oil. Set aside.

Take the beef out of the refrigerator so it can lose some of its chill while you prepare the buckwheat. This helps it sear more evenly.

Step 2: Toast and par-cook the buckwheat

Add the buckwheat groats to a dry, medium saucepan over medium heat. Toast, stirring frequently, for 3–5 minutes until the grains smell nutty and a few start to darken slightly. Watch closely so they do not burn.

Pour in 2 3/4 cups (650 ml) beef broth and add 1/2 teaspoon salt. Stir, bring to a gentle boil, then reduce heat to low. Cover and simmer for 10–12 minutes, just until most of the liquid is absorbed and the buckwheat is barely tender but not mushy. It should still have a little bite, as it will finish cooking in the oven.

Turn off the heat and let the buckwheat sit, covered, for 5 minutes, then fluff with a fork. Spread it evenly over the bottom of your prepared casserole dish in an even layer.

Step 3: Season and sear the beef strips

While the buckwheat cooks, pat the beef strips dry with paper towels. In a bowl, toss the beef with 1 teaspoon salt, 1/2 teaspoon black pepper, 1/2 teaspoon garlic powder, and 1 tablespoon flour until evenly coated.

Heat 2 tablespoons oil in a large, heavy skillet (cast iron works well) over medium-high heat until shimmering. Add the beef in a single layer, working in 2 batches if needed to avoid crowding. Sear for 1–2 minutes per side, just until nicely browned on the edges. The beef does not need to cook through at this stage.

Transfer the browned beef to a plate and set aside. Leave any drippings and browned bits in the pan for extra flavor.

Step 4: Sauté the onions, mushrooms, and aromatics

In the same skillet over medium heat (add a teaspoon or two of additional oil if the pan looks dry), add the sliced onions and a pinch of salt. Cook, stirring often, for 10–12 minutes until the onions are softened and turning golden around the edges.

If using mushrooms, add them after the onions have cooked for about 5 minutes. Continue cooking until the mushrooms release their moisture and start to brown.

Add the minced garlic and 1 teaspoon fresh thyme, and cook for 1 minute more, just until fragrant. Turn off the heat. Spread this onion (and mushroom) mixture evenly over the buckwheat layer in the casserole dish.

Arrange the seared beef strips on top of the onions in an even layer, pouring any accumulated juices from the plate over the beef.

Step 5: Make the creamy herb gravy

Return the same skillet to medium heat. Add 3 tablespoons butter. Once melted and foaming, sprinkle in 1/4 cup (30 g) flour. Whisk constantly for 1–2 minutes to form a smooth roux; it should look like a paste and smell lightly nutty, but not burned.

Slowly pour in 2 cups (480 ml) beef broth while whisking to avoid lumps. Once smooth, gradually add the 1 cup (240 ml) milk or half-and-half, continuing to whisk. Add the bay leaf, 1 teaspoon thyme, 1 tablespoon Worcestershire sauce, 1 teaspoon Dijon mustard, and 1/2 teaspoon smoked paprika.

Bring the mixture to a gentle simmer and cook for 4–6 minutes, stirring often, until thickened to a gravy-like consistency that coats the back of a spoon.

Turn off the heat. Remove the bay leaf. Whisk in the sour cream until smooth. Taste and season with 1/2 teaspoon salt and 1/4 teaspoon black pepper, adjusting to your preference. The gravy should be well-seasoned and flavorful, as it will season the buckwheat and beef.

Step 6: Assemble the casserole

Pour the hot creamy herb gravy evenly over the beef and onion layers in the casserole dish. Use a spatula or spoon to gently nudge the gravy into the corners and down between the beef strips, but avoid stirring the layers together too much. You want visible strata of buckwheat, onions, and beef.

Cover the dish tightly with aluminum foil. Place the casserole on a rimmed baking sheet if you are concerned about any bubbling over.

Step 7: Bake until bubbly, rest, and serve

Bake the covered casserole at 375°F (190°C) for 25 minutes. Then carefully remove the foil and bake for an additional 10–15 minutes, or until the sauce is bubbling around the edges and you see a few browned spots on top.

Remove from the oven and let the casserole rest for at least 10 minutes. This rest time allows the layers to settle and makes it easier to scoop tidy portions.

Sprinkle with chopped fresh parsley and a final grind of black pepper before serving. Ladle generous, rustic scoops into warm bowls or onto plates. The buckwheat should be tender and nutty, the beef juicy, and everything wrapped in a rich, creamy herb gravy.

Pro Tips

• Use the right beef cut: Sirloin or tri-tip will be more tender, while chuck gives bigger flavor but benefits from thinner slicing across the grain.
• Do not overcook the buckwheat: Slightly underdone on the stove is perfect, as it will finish in the oven. Overcooked buckwheat can turn mushy.
• Brown, do not steam: Sear the beef in batches and avoid crowding the pan so you get good browning and flavor instead of gray, steamed meat.
• Adjust gravy thickness: If the gravy seems too thick, whisk in an extra splash of broth or milk. If too thin, simmer a few more minutes before adding the sour cream.
• Let it rest: The 10-minute rest after baking helps the casserole set and makes for neater, more satisfying servings.

Variations

• Mushroom-forward version: Double the mushrooms to 2 cups and add an extra 1/2 teaspoon thyme. This boosts the earthy flavor and makes the dish even cozier.
• Cheesy top: During the last 10 minutes of baking, sprinkle 1–1 1/2 cups shredded Gruyère or Swiss cheese over the top for a gratin-style finish.
• Lighter dairy option: Use 2% milk and plain Greek yogurt instead of sour cream. The gravy will be slightly tangier and lighter but still creamy.

Storage & Make-Ahead

Let the casserole cool to room temperature, then cover tightly.

Refrigerator: Store in the fridge for up to 4 days. Reheat individual portions in the microwave, or rewarm the whole dish covered with foil in a 350°F (175°C) oven for 20–25 minutes, until hot in the center.

Freezer: This casserole freezes well. Cool completely, wrap tightly in plastic wrap and foil, and freeze for up to 2 months. Thaw overnight in the refrigerator, then reheat at 350°F (175°C), covered, for 30–40 minutes, or until piping hot.

Make-ahead: You can assemble the entire casserole up to the point of baking, cover, and refrigerate for up to 24 hours. Add about 10 extra minutes to the covered baking time to account for the chilled dish.

Nutrition (per serving)

Approximate values per serving (1/6 of the recipe): about 480 calories; 30 g protein; 34 g carbohydrates; 23 g fat; 9 g saturated fat; 3 g fiber; 900 mg sodium. Actual values will vary based on specific ingredients and brands used.