Tuna Fish without butter gelatin eggs

1 1/2 lbs potatoes , peeled 2 cups white sauce 370 g tuna in vegetable oil mature cheddar cheese 2 Tomatoes , sliced salt white pepper butter 2 tablespoons[...]

36 ounces ahi tuna steaks , 1-inch thick (or 4 boneless skinless chicken breasts) 2 tablespoons olive oil or 2 tablespoons peanut oil fresh ground pepper 3[...]