1. Preheat the oven to 350°F.
2. In a medium skillet, heat the butter over medium heat. Add the red onion and bell pepper, cooking for 3-5 minutes until softened. Remove from heat.
3. In a blender, combine the eggs, cottage cheese, seasonings, and mustard. Blend until smooth.
4. Spoon the red bell pepper and onion mixture into a silicone muffin mold, dividing it equally among 12 cups.
5. Pour the egg mixture into each cup, filling about ¾ full.
6. Top each with crumbled feta.
7. Bake for 17-20 minutes until edges are set and centers are cooked.
8. Cool for 5 minutes, then gently remove from the mold. Add crushed red pepper flakes if desired. Serve immediately.

PREP TIME & NUTRITION:
Prep Time: 10 minutes, Servings: 12, Calories: 120, Net Carbs: 2g, Fats: 8g, Protein: 10g