Vegan Lentil-Stuffed Peppers

Preheat the oven to 350 degrees F (175 degrees C).

Heat oil in a large skillet over medium-high heat. Add onion and broth and cook for 3 minutes. Stir in mushrooms, garlic, Italian seasoning, vinegar, salt, and crushed red pepper flakes; cook for 2 minutes. Remove from heat and stir in lentils and spinach.

Place bell peppers in a baking dish and divide filling between both peppers. Cover dish with foil.

Bake in the preheated oven for 20 minutes. Uncover and continue cooking for 10 minutes, or until peppers reach desired softness.