Preheat oven to 400 degrees and spray 12-cup muffin tin with nonstick olive oil spray.
Place a scoop of shredded potatoes into each muffin cup, pressing around edges to create a “nest.”
Bake for 15–20 minutes or until lightly golden. Remove pan from oven and using a spoon, gently press any fallen potatoes back up against sides of each muffin cup. Reduce heat to 350 degrees.
In a bowl, add eggs, egg whites, ¼ cup milk, salt and pepper.
Whisk to combine; place bowl in fridge while you dice and chop the green pepper, tomatoes and any other veggies you want to add.
Stir the cooked meat and vegetables into the bowl with egg mixture and pour equally between all nests. Sprinkle a pinch of cheese over each nest. Bake for 15–20 minutes or until eggs are set, then remove the muffin tin from oven.