Preheat oven to 350°. Brown hamburger and onion in large skillet on medium heat. Drain fat.Add ketchup, salt, garlic powder, onion powder, taco seasoning, refried beans and Tabasco. Mix well and stir occasionally for another 3 minutes.Put half of the meat mixture into a greased casserole dish. Add half of the cheddar and jack cheese. Then layer the rest of the meat mixture on top. Add the remaining cheese. Cover with aluminum foil and bake for 45 minutes. Remove the foil and continue baking for another 10 minutes or until the sides are bubbling and the cheese is all melted on top.Remove the casserole dish and garnish the top with olives, tomato and green onions. Serve with tortilla chips.