Cut the salmon into cubes and chop, but not too finely. In a glass bowl combine the salmon, red pepper, green onion, mint and mayonnaise. Bind the mixture with the egg and breadcrumbs then season with salt and pepper. Refrigerate the mixture so it is easier to shape into cakes.
When you are ready to eat, season the flour mixture with salt and pepper. Shape the salmon mixture into four cakes. Heat 2 tablespoons of vegetable oil in a large nonstick 12 inchskillet. Lightly dredge each salmon cake in flour and cook, adjusting heat as necessary and turning once, anywhere from 5 to 10 minutes, depending upon how well cooked you like your fish to be. The less time they cook, the moister they will be. Set each salmon cake on a warm bun garnished with the mayonnaise, arugula and tomatoes. Eat as open an faced sandwich with a knife and fork Serve with steamed zucchini or yellow squash salad.