Step 1: Preheat the Oven

1. Preheat your oven to 350°F (175°C). Grease a 12-cup muffin tin with cooking spray or line it with silicone baking cups for easy cleanup.

Step 2: Prepare the Egg Mixture

1. In a large mixing bowl, whisk together the egg whites, cottage cheese or Greek yogurt (if using), salt, and black pepper until smooth and frothy.

Step 3: Add the Vegetables and Protein

1. Evenly divide the spinach, red bell pepper, onions, and cooked sausage among the muffin cups. You can mix and match ingredients to customize the flavors in each cup.
2. Pour the egg white mixture over the vegetables and protein, filling each muffin cup about three-quarters full.

Step 4: Bake the Egg White Bites

1. Place the muffin tin in the preheated oven and bake for 18–20 minutes, or until the egg white bites are set and lightly golden around the edges.
2. Remove from the oven and let them cool in the tin for 5 minutes before transferring them to a wire rack.

Step 5: Serve and Enjoy

1. Serve the egg white bites warm with optional toppings like fresh herbs or avocado slices.
2. Store leftovers in an airtight container in the refrigerator for up to 4 days or freeze for up to 2 months.