Preheat your oven to 375°F (190°C). Using a small paring knife, carefully carve faces with simple eyes, nose, and mouth shapes into each bell pepper, creating a cheerful jack-o'-Lantern appearance. Remove the tops and seeds, then set them aside for roasting or composting.
In a mixing bowl, combine cooked rice or quinoa, shredded cheese, diced zucchini, chopped onion, and minced garlic. Season with salt and pepper, then stir until all ingredients are well mixed and slightly sticky.
Heat olive oil in a skillet over medium heat. Add the chopped onion and minced garlic, sautéing until fragrant and translucent, about 2-3 minutes. Add the zucchini and cook for another 3-4 minutes until tender and slightly browned.
Stir the cooked vegetable mixture into the bowl with the rice and cheese, mixing everything thoroughly to create the filling. Adjust seasoning if needed.
Spoon the filling into each carved bell pepper, pressing gently to pack in the mixture. Fill them nearly to the top for a generous presentation.
Arrange the stuffed peppers on a baking sheet lined with parchment paper. Place the tops of the peppers back on if desired for a more traditional look.
Bake in the preheated oven for about 35-40 minutes, or until the peppers are tender and the cheese is melted and bubbling around the edges. The carved faces will turn slightly roasted with caramelized spots.
Remove from the oven, let cool slightly, and serve hot. The vibrant peppers with melted cheese and playful faces make a fun and colorful meal.
