This is a dish my parents used to be able to make in a half hour when we were children. I added a few additions to make it a little more exciting and fairly low in fat. Serve on hamburger buns with traditional hamburger condiments if desired.
Preheat oven to 375 degrees F (190 degrees C). Spray a baking sheet with cooking spray.
Mix tuna, egg, bread crumbs, garlic salt, and black pepper and fold in diced tomatoes and onion. Form the mixture into 4 patties and place onto prepared baking sheet.
Bake in the preheated oven until burgers are golden brown and crisp, about 10 minutes per side.
Per Serving: 156 calories; protein 19.9g; carbohydrates 12.2g; fat 2.5g; cholesterol 65.4mg; sodium 536.6mg.