Combine ham or sausage with onions, place about ⅓ cup down the center of each of each tortilla. Top with 2 tablespoons cheese.
Roll up and place seam side down in a greased 9 by 9 inch baking dish.
In a bowl combine flour, milk, eggs, and salt until smooth.
Pour over tortillas.
Cover and refrigerate overnight or 8 hours.
Remove from fridge 30 minutes before baking.
Bake covered at 350 for 25 minutes.
Uncover and bake an additional 10 minutes.
Sprinkle with remaining cheese. Bake 3 minutes or until cheese is melted.
Let stand for for a few minutes before serving.