Cheese-Stuffed Portobello Mushrooms with Spinach and Pine Nuts

By , Test Kitchen Director · Reviewed by AislePrompt Editorial · ·

Large Portobello mushroom caps filled with sautéed spinach, toasted pine nuts, and melted cheese for a satisfying keto vegetarian entrée. This mediterranean-inspired keto (vegetarian, low carb) ready in about 30 minutes pairs large Portobello mushroom caps, divided olive oil, minced garlic for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 280 calories and feeds 4, so it slots cleanly into a weekly meal plan and pairs well with a quick salad or grain on the side. Tap "Plan a meal with the AI" below to drop this recipe into your week and send the ingredients straight to Instacart. Nutrition values are approximate, calculated from USDA FoodData Central (fdc.nal.usda.gov) — verify against ingredient labels for any health-driven dietary plan.

Prep: 10 min Cook: 20 min Serves 4 Mediterranean cuisine 280 cal/serving
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Ingredients

Instructions

  1. Step 1: Preheat oven to 375°F. Clean 4 large Portobello mushroom caps and remove stems. Brush each cap with 2 tbsp olive oil and sprinkle with 1/2 tsp salt and 1/4 tsp black pepper. Place on a baking sheet gill-side up.
  2. Step 2: Heat 1 tbsp olive oil in a large skillet over medium heat. Add 3 minced garlic cloves and sauté for 30 seconds until fragrant.
  3. Step 3: Add 5 cups packed fresh spinach to the skillet and cook for 3-4 minutes, stirring frequently, until wilted. Stir in 1/3 cup pine nuts, 1/2 tsp salt, 1/4 tsp black pepper, and 1/2 tsp dried oregano. Remove from heat.
  4. Step 4: Divide the spinach mixture evenly among the mushroom caps. Top each with 1/4 cup shredded mozzarella and 1 tbsp grated Parmesan cheese.
  5. Step 5: Bake mushrooms in the preheated oven for 15-18 minutes until the cheese is melted, bubbly, and golden around the edges.

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Frequently asked questions

How long does Cheese-Stuffed Portobello Mushrooms with Spinach and Pine Nuts take to make?

Total time is about 30 minutes (10 min prep + 20 min cook). Most home cooks find this fits comfortably into a weeknight; double the batch on Sunday for two dinners.

How do I store leftover Cheese-Stuffed Portobello Mushrooms with Spinach and Pine Nuts?

Cool to room temperature within 2 hours, then store in an airtight container in the fridge for up to 4 days. Reheat covered in a 350°F oven for 10-12 minutes, or microwave at 70% power in 60-second bursts to keep divided olive oil from drying out.

Can I substitute ingredients in Cheese-Stuffed Portobello Mushrooms with Spinach and Pine Nuts?

Yes — most ingredients in this recipe have flexible swaps. For oil, use any neutral high-smoke-point oil (avocado, grapeseed, refined coconut). For aromatics, dried herbs at ⅓ the volume of fresh work in a pinch. The full ingredient list is shoppable on Instacart so you can see substitutes in real time.

How do I scale Cheese-Stuffed Portobello Mushrooms with Spinach and Pine Nuts for a different number of people?

The recipe is written for 4 servings. Multiply each ingredient by (your serving target / 4). Cook time stays roughly the same up to 2x; for 3-4x batches, switch from a skillet to a sheet pan or stockpot so the food isn't crowded — overcrowding steams instead of browns.

Is Cheese-Stuffed Portobello Mushrooms with Spinach and Pine Nuts vegetarian?

Yes — this recipe is tagged vegetarian, low carb, gluten free based on its ingredient list. Always cross-check labels for packaged ingredients (sauces, broths, condiments) since formulations vary by brand.

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