Step 1

In a large bowl, combine tomatoes and onion, set aside.

Step 2

In a small saucepan, combine vinegar, sugar, water, red pepper flakes, and cayenne pepper. Bring to a boil over medium-high heat and boil 1 minute.

Step 3

Pour fat free salad dressing over the tomatoes and onions. Toss to coat. Cover and refrigerate for at least 2 hours (overnight is best).

Step 4

Add sliced cucumber and toss to coat. Serve cold.