Preheat your oven to 375°F (190°C). Carefully wash the peppers and slice off the tops to create a lid, then scoop out the seeds and membranes with a spoon, smoothing the interior. Set aside the tops for carving or decoration.
Mix the shredded cheese, cooked rice or quinoa, spices, cooked protein, and an egg in a bowl until well combined. This mixture will be the filling that gives the peppers flavor and texture.
Stuff each hollowed pepper with the filling, pressing gently to pack it in but avoiding overflow. Place the stuffed peppers upright on a baking sheet lined with parchment or foil.
Carve small faces or pumpkin-like indentations into the pepper tops if desired, for a festive look. Place these on top of the stuffed peppers or set aside for decoration.
Bake the peppers in the preheated oven for about 25-30 minutes, until the peppers are tender and slightly charred around the edges, and the filling is bubbling and golden.
Remove from the oven, and let the peppers cool for a few minutes. Garnish with additional cheese, herbs, or decorations if desired, then serve hot, showcasing their vibrant colors and playful faces.