Grate your favorite cheese. Slice tomatoes and place on a griddle or in skillet drizzled with a little olive oil. Add pepper/salt if desired. Cook for just a couple of minutes till tomatoes become tender.
This is the chili sauce I used.
Spread chili sauce onto one side of each tortilla. You will want the chili sauce to be on the INSIDE of the quesadilla. Spray griddle or skillet with non stick spray, place plain side of tortilla on bottom.
Sprinkle with a little cheese, then add tomato slices, cilantro, more cheese, then other tortilla. Spray the top side of the tortilla with spray oil to help in the browning and crisping process. Cook over med. high-high heat on each side for a couple of minutes, just until cheese melts and tortilla browns a little and becomes crispy.