Preparation time: 27 minutes Heat oven to 400 degrees F. Brown ground beef and onion in skillet over medium heat 8 to 10 minutes or until beef is no longer pink. Pour off drippings.
Stir oregano and salt into the meat. Lightly brush tortillas with oil Bake tortillas on 2 large baking sheets in 400 degree F. oven 3 minutes. Spoon beef mixture evenly over top of each tortilla; top with an equal amount of tomato. Sprinkle with basil and cheeses.
Return to the oven and bake 12 to 14 minutes or until tortillas are lightly browned. Serving suggestion: