Preheat your oven to 375°F (190°C) and lightly grease a muffin tin.
Heat avocado oil in a skillet over medium heat.
Add white parts of green onions, bell pepper, and beef sausage. Cook until slightly browned.
Season with sea salt, oregano, and black pepper.
Stir in spinach and cook until wilted. Remove from heat.
In a bowl, whisk eggs, cottage cheese, kosher salt, and pepper until smooth.
Evenly divide the cooked mix-ins into muffin cups.
Pour the egg mixture over the filling.
Sprinkle goat cheddar and remaining green onions on top.
Bake for 18–22 minutes until set.
These High-Protein Meal Prep Egg Cups should be fully cooked but still moist in the center.