01 - Preheat oven to 350°F (180°C). Coat a 12-cup muffin tin with olive oil or nonstick spray.
02 - Warm olive oil in a skillet set over medium heat. Sauté diced bell pepper and zucchini for 3–4 minutes until slightly tender. Transfer to a plate and cool briefly.
03 - In a large mixing bowl, combine eggs, milk, salt, black pepper, and smoked paprika, whisking until fully blended.
04 - Incorporate sautéed vegetables, chopped spinach, sliced spring onions, and shredded cheddar cheese into the egg mixture, mixing thoroughly.
05 - Distribute the mixture evenly among muffin cups, filling each about three-quarters full. Bake for 18–20 minutes, until set and lightly golden.
06 - Allow muffins to cool for 5 minutes in the tin, then carefully remove. Enjoy warm or at room temperature.