Swiss Steak with Tomato Gravy

1 large slice round steak
1/2 cup vegetable oil
2 large cans tomatoes
1 cup all-purpose flour
1 large onion, diced
Salt and pepper
1 cup water (for gravy)

Spray crockpot with Pam. Turn on LOW.

Heat oil in large skillet. Cut round steak in serving-size pieces. Put flour into a shallow pan. Add salt and pepper to flour and flour steak well.

Fry steak in hot oil until brown. Pour a few tomatoes into the crockpot. Add pieces of browned steak and remaining  tomatoes in layers. Add diced onion. Cook for 4 hours on LOW heat.

Remove meat. Put 1 cup of water in a pint jar. Add 3 tablespoons flour. Shake well. Add to tomato mixture in the crockpot. Cook and stir until gravy is thickened. Put meat back in long enough to heat.

Serve with mashed potatoes.