01 - Preheat the oven to 350°F (180°C). Grease a 12-cup muffin tin.
02 - In a skillet over medium heat, cook the breakfast sausage, breaking it apart with a spoon, until thoroughly browned. Drain any excess fat and set aside.
03 - In a large bowl, whisk together the eggs, milk, salt, black pepper, and optional smoked paprika until well combined.
04 - Fold the cooked sausage, diced red bell pepper, chopped spinach, sliced spring onions, and shredded cheddar cheese into the egg mixture. Stir to ensure even distribution.
05 - Evenly divide the mixture among the prepared muffin cups, filling each approximately three-quarters full.
06 - Bake for 22 to 25 minutes, or until the muffins are set and have a lightly golden appearance.
07 - Allow the muffins to cool in the tin for 5 minutes before removing. Serve warm or at room temperature.