1. Preheat oven to 350F. In a medium sized bowl, combine ground beef, oats, ketchup, egg and salt.
2. Form into a 8 inch diameter pattie. Place pattie on broiler pan and bake for 40 to 45 minutes, until juices run clear.
3. Place cheese slices on top of pattie, bake for 1 more minute to melt the cheese.
4. Cut bread in half horizontally, making a big hamburger bun. Place pattie inside bun, add lettuce, and cut into 8 wedges.