Fry the sausage, breaking it into small pieces as it fries.
Break the eggs into a bowl and add the milk. Mix with a fork. Melt butter in a skillet and pour egg mixtue into it. Add sausage pieces when eggs begin to set. Cook, stirring with a fork occasionally until eggs are cooked through.
Butter one side of 4 tortillas. Place one tortilla butter side down on a moderately hot griddle or in a skillet. Spread half the scrambled egg mixture over the tortillas. Spread half of the grated cheese on top of the eggs. Place a second tortilla, butter side up on top. Cook until bottom tortilla is slightly browned. Carefully turn and slightly brown the top tortilla. Make a second quesadilla in the same way using the remaining scrambled eggs.
Serve with salsa and sour cream. Garnish with avocado slices.
Salsa: Drain the canned tomatoes. Chop fine in a food processor. Add sliced green onions, cumin, coriander and balsamic vinegar. Chop the chipotle pepper and add to mixture.