This is one of my favorite recipes. Although I use cubed steaks, you can use tenderized round steak.

4 cubed steaks
Salt, pepper, garlic salt, & onion salt to taste
1 small onion, sliced
1/4 cup chopped green pepper
Mustard
1 14.5-oz. can stewed tomatoes
1/4 cup water

Dredge steaks in flour, season on both sides and brown in small amount of hot oil. Pour off grease. Slice onion on top of steaks; add chopped peppers. Drizzle mustard over top of all. Add tomatoes and water. Simmer for about an hour until very tender.