Breakfast Egg Muffins (Frittata Muffins)

Bahan-bahan (12 porsi)

• 8 large eggs
• 1/3 cup (80ml) whole milk or half-and-half (or nondairy milk)
• 1/4 teaspoon salt
• 1/4 teaspoon freshly ground black pepper
• 1/4 teaspoon onion powder
• 1/4 teaspoon garlic powder
• 3/4 cup (120g) finely chopped bell pepper (any color)
• 1/2 cup (75g) finely chopped tomatoes
• 1/2 cup (15g) finely chopped fresh spinach (or kale)
• 3/4 cup (100g) crumbled feta cheese
• optional for garnish: chopped parsley or chives, grated parmesan cheese, or red pepper flakes