Portobello Mushroom Lasagna with Ricotta and Spinach

By AislePrompt Test Kitchen · Reviewed by AislePrompt Editorial · Published 2026-05-12 · Updated 2026-05-12

A savory vegetarian lasagna layering grilled Portobello mushrooms, creamy ricotta, and wilted spinach for a satisfying meatless meal. This italian-inspired vegetarian (vegetarian) ready in about 65 minutes pairs olive oil, minced garlic cloves, roughly chopped fresh spinach for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 410 calories and feeds 6, 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.

Ingredients

• 6 caps, sliced into 1/4-inch strips large Portobello mushrooms
• 4 tbsp olive oil
• 4 minced garlic cloves
• 5 cups, roughly chopped fresh spinach
• 1 1/2 cups ricotta cheese
• 2 cups shredded mozzarella cheese
• 1/2 cup grated Parmesan cheese
• 9 pieces, cooked al dente lasagna noodles
• 3 cups marinara sauce
• 1 1/2 tsp divided salt
• 1/2 tsp divided black pepper
• 1/4 tsp optional red pepper flakes

Instructions

1. Step 1: Preheat oven to 375°F. Heat 2 tbsp olive oil in a large skillet over medium heat. Add 4 minced garlic cloves and sauté for 30 seconds until fragrant, then add 5 cups chopped fresh spinach, 3/4 tsp salt, and 1/4 tsp black pepper. Cook for 3 minutes until spinach is wilted; set aside.
2. Step 2: In the same skillet, heat remaining 2 tbsp olive oil over medium-high heat. Add 6 sliced Portobello mushroom caps and sauté for 6-8 minutes until tender and starting to brown, seasoning with 3/4 tsp salt, 1/4 tsp black pepper, and 1/4 tsp red pepper flakes if using.
3. Step 3: In a bowl, combine 1 1/2 cups ricotta cheese with the cooked spinach mixture.
4. Step 4: In a 9x13 inch baking dish, spread 1/2 cup marinara sauce on the bottom. Layer 3 cooked lasagna noodles, half the ricotta-spinach mixture, half the mushrooms, 1 cup marinara sauce, and 2/3 cup shredded mozzarella. Repeat the layers ending with noodles topped with remaining marinara and 1 cup mozzarella and 1/2 cup grated Parmesan.
5. Step 5: Cover with foil and bake for 25 minutes. Remove foil and bake an additional 15 minutes until cheese is bubbly and golden. Let rest 10 minutes before slicing.