Preheat oven to 375 degrees and spray a 2 qt. rectangular baking dish with non-stick spray or line with non-stick foil.
Brown ground beef and onion in a large skillet; pour off drippings (and if you want to get the majority of the grease off of ground beef, rinse the mixture with hot water before you proceed).
Sprinkle meat mixture with garlic salt and pepper flakes; remove from heat and stir in 1/2 cup pasta sauce and
1 1/2 cups of cheese.
Spoon 1 cup pasta sauce into prepared baking dish. Spoon 1/4 cup of meat mixture down the center of each lasagna noodle; roll up and place seam side down in baking dish. Spoon remaining sauce over roll-ups.
Cover with foil (again, non-stick foil works best) and bake in preheated oven for 35 minutes or until heated through.
Remove from oven; uncover and sprinkle with remaining cheese. Let stand 5 minutes before serving.