In a bowl, whisk together eggs, milk, salt, and pepper.
Heat olive oil in a skillet over medium heat.
Add onions and bell peppers, cooking until softened.
Push vegetables to the side of the skillet and pour in the egg mixture.
Scramble the eggs until just set, then stir in the cooked sausage and cheese.
Warm the tortillas in a separate skillet or microwave.
Divide the egg mixture among the tortillas, fold in the sides, and roll up.
Serve with salsa and sour cream.