In a skillet, cook the chopped bacon until it’s crispy, then transfer to a bowl and discard the excess grease.
In a separate bowl, whisk together eggs, milk, salt, and pepper until well combined.
Using the same skillet, melt the butter over medium heat. Pour in the egg mixture and let it cook undisturbed for about 15-20 seconds until the edges begin to set. Then, gently stir with a spatula, breaking the eggs into soft curds. Once the eggs are fully cooked but still slightly creamy, remove them from the heat and set aside.
In the same pan, cook the crumbled breakfast sausage with the chopped onion and red bell pepper until the sausage is browned and the onion is softened.
Assembling Quesadilla - Method 1:
Sprinkle cheese on one half of each tortilla. Add the scrambled eggs, sausage mixture, crispy bacon, and green onions. Sprinkle more cheese on top, then fold the tortilla over.
Assembling Quesadilla - Method 2:
Lay one tortilla flat and spread a layer of shredded cheese, leaving a small border around the edges. Add the scrambled eggs, sausage mixture, crispy bacon, and green onions, then sprinkle more cheese on top. Place another tortilla on top.
Cooking Quesadillas:
Place the filled tortillas in a hot non-stick skillet. Cook until the cheese melts and the tortilla is golden and crisp, about 2-3 minutes per side. Flip and cook for another 2-3 minutes until both sides are crisp.
Transfer the quesadillas to a cutting board, slice them into wedges, and serve with sour cream or salsa.