Garlic Oil Grilled Veggie-Stuffed Portobello Mushrooms

Quick Recipe Version (TL;DR)

• Yield: 4 stuffed portobello mushrooms (serves 4 as a light main or 2 as a hearty main)
• Prep Time: 20 minutes
• Cook Time: 15 minutes
• Total Time: 35 minutes

Quick Ingredients

• 4 large portobello mushroom caps (about 4–5 inches wide)
• 1/4 cup (60 ml) extra-virgin olive oil
• 3 garlic cloves, minced (about 1 Tbsp)
• 1/2 tsp kosher salt, plus more to taste
• 1/2 tsp smoked paprika
• 1/4 tsp black pepper
• 1 small zucchini, diced (about 1 1/4 cups / 170 g)
• 1 red bell pepper, diced (about 1 cup / 150 g)
• 1/2 small red onion, diced (about 3/4 cup / 110 g)
• 1 cup (30 g) baby spinach, chopped
• 1/2 cup (85 g) cherry tomatoes, halved
• 1/2 cup (90 g) cooked quinoa (or cooked farro)
• 3 Tbsp (15 g) grated Parmesan (or crumbled feta)
• 1 Tbsp (15 ml) balsamic vinegar (optional)
• 2 Tbsp (8 g) chopped parsley (or basil)

Do This

• 1) Heat grill to 450°F (232°C) (medium-high). Clean and oil grates.
• 2) Remove portobello stems; scrape out gills. Brush caps with garlic oil.
• 3) Cook diced zucchini, pepper, and onion in a grill-safe skillet with a little garlic oil, 6–8 minutes.
• 4) Stir in spinach, tomatoes, quinoa, Parmesan, and (optional) balsamic; cook 1–2 minutes.
• 5) Fill mushroom caps. Grill caps gill-side up, lid closed, 6 minutes.
• 6) Flip carefully; grill 4–6 minutes more until tender, smoky, and lightly charred.
• 7) Rest 3 minutes, sprinkle herbs, and serve hot.

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Why You’ll Love This Recipe

• Big flavor, simple steps: garlic oil + high-heat grilling equals smoky, savory goodness.
• Hearty and satisfying: stuffed portobellos eat like a main dish, even without meat.
• Flexible: swap in your favorite vegetables, grains, and cheeses.
• Great for grilling season: everything can be cooked outdoors with minimal kitchen mess.

Grocery List

• Produce: 4 large portobello mushroom caps, 1 small zucchini, 1 red bell pepper, 1/2 small red onion, baby spinach, cherry tomatoes, garlic, parsley (or basil)
• Dairy: Parmesan (or feta)
• Pantry: extra-virgin olive oil, quinoa (or farro), smoked paprika, kosher salt, black pepper, balsamic vinegar (optional)

Full Ingredients

Portobellos

• 4 large portobello mushroom caps (about 4–5 inches wide)
• 1/4 tsp kosher salt (for the mushrooms, from the total)

Garlic Oil (for brushing and cooking)

• 1/4 cup (60 ml) extra-virgin olive oil
• 3 garlic cloves, minced (about 1 Tbsp / 9 g)
• 1/2 tsp smoked paprika
• 1/4 tsp freshly ground black pepper
• 1/2 tsp kosher salt
• 1 tsp lemon juice (5 ml) (optional, for brightness)

Veggie Stuffing

• 1 small zucchini, diced (about 1 1/4 cups / 170 g)
• 1 red bell pepper, diced (about 1 cup / 150 g)
• 1/2 small red onion, diced (about 3/4 cup / 110 g)
• 1 cup (30 g) baby spinach, roughly chopped
• 1/2 cup (85 g) cherry tomatoes, halved
• 1/2 cup (90 g) cooked quinoa (or cooked farro)
• 1 Tbsp (15 ml) balsamic vinegar (optional, for a smoky-sweet finish)

Finish

• 3 Tbsp (15 g) grated Parmesan (or 1/3 cup / 50 g crumbled feta)
• 2 Tbsp (8 g) chopped parsley (or basil)
• Extra kosher salt and black pepper, to taste

Step-by-Step Instructions

Step 1: Preheat the grill and set up for high heat

Preheat a gas or charcoal grill to 450°F (232°C) (medium-high). Clean the grates well, then lightly oil them by wiping with a folded paper towel dipped in a little oil (use tongs for safety).

Set a grill-safe cast iron skillet or a grill basket over the heat so it preheats while you prep. This helps the vegetables cook quickly and pick up a little char.

Step 2: Prep the portobellos for stuffing

Gently wipe the mushroom caps clean with a damp paper towel. Remove the stems. Using a spoon, scrape out the dark gills (this creates more space for the filling and keeps the stuffing from turning muddy in color).

Lightly season the inside of each cap with about 1/16 tsp salt (a small pinch each), taken from the total salt.

Step 3: Make the garlic oil

In a small bowl, stir together the olive oil (1/4 cup / 60 ml), minced garlic, smoked paprika, black pepper, kosher salt (1/2 tsp), and lemon juice (1 tsp) if using.

Brush a thin, even layer of garlic oil over the outside and inside of each mushroom cap. Reserve the remaining garlic oil for cooking the filling and for a final brush right before serving.

Step 4: Cook the veggie stuffing until crisp-tender

Add 1 Tbsp (15 ml) of the garlic oil to the preheated cast iron skillet (or grill-safe pan). Add the diced zucchini, bell pepper, and red onion. Cook, stirring occasionally, until the vegetables are crisp-tender and lightly charred in spots, about 6–8 minutes.

Stir in the spinach and cook until just wilted, about 30–60 seconds. Add the cherry tomatoes and cooked quinoa and cook until warmed through, about 1 minute. If using, stir in the balsamic vinegar (1 Tbsp / 15 ml) and cook for 30 seconds to take the raw edge off.

Remove the skillet from heat. Stir in 2 Tbsp (10 g) Parmesan (reserve 1 Tbsp for the top) or half the feta if using. Taste and adjust with a pinch of salt and pepper if needed.

Step 5: Stuff the mushrooms securely

Place the portobello caps on a tray. Spoon the hot veggie mixture into each cap, packing it gently so it mounds up without falling out. Aim for an even split: about 3/4 cup stuffing per mushroom.

Sprinkle the tops with the remaining 1 Tbsp Parmesan (or remaining feta).

Step 6: Grill until tender, smoky, and charred at the edges

Place the stuffed mushrooms on the grill over direct heat. Start with the mushrooms gill-side up (stuffing facing up). Close the lid and grill for 6 minutes, until the bottoms develop grill marks and the caps begin to soften.

Using a wide spatula and tongs, carefully flip the mushrooms gill-side down (stuffing facing down) and grill with the lid closed for 4–6 minutes, until the mushrooms are tender and the edges are deeply browned and smoky. The stuffing should be heated through and lightly charred in places.

If your grill runs hot and you’re worried about the stuffing falling out, you can instead move the mushrooms to indirect heat after the first 6 minutes and finish them stuffing-side up for 6–8 minutes with the lid closed.

Step 7: Rest, finish with herbs, and serve

Transfer the mushrooms to a plate and let them rest for 3 minutes (this helps the juices settle and makes them easier to eat). Brush lightly with a final teaspoon or two of the reserved garlic oil for extra shine and flavor.

Sprinkle with chopped parsley (or basil). Serve hot.

Pro Tips

• Scrape the gills: It makes more room for filling and keeps the stuffing brighter in color.
• Use a hot pan for the filling: Preheating the cast iron skillet on the grill helps the vegetables char instead of steaming.
• Don’t over-oil the mushrooms: A thin brush is plenty; too much oil can cause flare-ups.
• Flip with support: Use a wide spatula under the cap and tongs to steady the top for the cleanest flip.
• Check doneness by feel: Portobellos are ready when they’re pliable and juicy, not shriveled.

Variations

• Mexican-inspired: Swap quinoa for cooked black beans (1/2 cup), add 1/2 tsp ground cumin, and finish with crumbled cotija and lime.
• Mediterranean: Use feta, add 2 Tbsp chopped kalamata olives, and finish with oregano and a squeeze of lemon.
• Extra smoky: Add 1/2 tsp chipotle powder to the garlic oil and top with a spoonful of smoky tomato salsa.

Storage & Make-Ahead

Store leftovers in an airtight container in the refrigerator for up to 3 days. Reheat on a sheet pan in a 375°F (190°C) oven for 10–12 minutes, or warm in a covered skillet over medium-low heat for 6–8 minutes. For make-ahead, cook the stuffing up to 2 days in advance and refrigerate; stuff the mushrooms right before grilling for the best texture.

Nutrition (per serving)

Approximate, per 1 stuffed mushroom (1/4 of recipe): 260 calories, 15 g fat, 24 g carbs, 8 g protein, 6 g fiber, 520 mg sodium.