Preheat the oven to 350 °F (177 °C). Spray a 24 cup mini muffin pan with non stick cooking spray.
Add the olive oil to a skillet or saucepan over medium heat. Once it's hot, add in the bell pepper. Cook, while stirring occasionally, for about 5 minutes or until softened.
1 Tablespoon Olive Oil, ½ Cup Red Bell Pepper
Add the spinach to the pan and cook while stirring for about 2-3 minutes or until wilted.
1 ½ Cups Baby Spinach
Divide the cooked vegetables between the muffin cups in the prepared pan.
In a large bowl, combine the eggs, milk, salt and pepper (add more or less to taste). Whisk together until combined.
6 large Eggs, ¼ Cup Non Dairy Milk, ½ teaspoon Kosher Salt, ¼ teaspoon Black Pepper
Sprinkle the shredded cheese and green onions over the vegetables.
⅔ Cup Shredded Cheese, 1 bunch Green Onions
Place the muffin tin on a rimmed baking sheet. Then pour the eggs into the muffin cups until all of the vegetables and cheese are covered.
Bake in the preheated oven for 10-12 minutes. The mini muffins are done when the middles are set and spring back when touched.
Remove from the oven and allow them to cool in the pan for a few minutes. Some sinking in the center is normal. Slide a knife around the edge of the pan to loosen the muffins if necessary, then transfer them to a serving plate or cooling rack. Cool completely before storing.
Notes
STORAGE: Store leftover egg muffins in an airtight container in the refrigerator for up to 4 days.