To prepare a good habit tuna melt main dish recipe, you'll first need to prepare the ingredients for the dish. You can find this at your local grocery store, or you can make it at home by following the instructions on the package. Heat 2 tablespoons olive oil over medium-high heat. Add 2 chopped red bell peppers and cook until softened, about 3 minutes. Stir in 2 teaspoons red pepper flakes and 1 teaspoon kosher salt. Remove from heat and stir in 1/2 cup chopped scallions. Season with salt and pepper to taste. Spoon the mixture into 4 ramekin-sized serving bowls. Top each bowl with 2 slices of toasted bread.