Cook spaghetti. Brown beef, then add onion salt, garlic, salt, pepper, chili powder, tomato sauce and water. Simmer slowly for 30 minutes. Combine sauce, spaghetti and 1/2 cup shredded cheddar cheese. Put mixture in casserole and add 1 cup shredded cheddar cheese on top. Bake at 350 degrees for 45 minutes with cover off. (If more liquid is needed, add another can of tomato sauce.)