A classic tuna melt with a tangy twist!
Preheat oven to 425 degrees F.
Spray a baking sheet with cooking spray.
In a medium bowl, combine tuna, onion, banana peppers and lemon juice. Lay bread on baking sheet.
Spoon and divide tuna mixture on the bread slices.
Top each tuna melt with two slices of tomatoes and then 2 slices of provolone cheese.
Bake in oven for 8-10 minutes, or until cheese is hot, bubbly, and starting to brown. Serve immediately.