Cut the beef into 6 serving-size pieces.
1 1/2 pounds boneless beef round steak
In a small bowl, stir together the flour, ground mustard, and salt. Sprinkle half of the flour mixture over one side of the beef and pound it in using a meat mallet. Turn the beef over and repeat with the remaining flour mixture. This helps tenderize the meat and gives the sauce more body as it cooks.
3 Tablespoons all-purpose flour, 1 teaspoon ground mustard, 1/2 teaspoon salt
Heat the vegetable oil in a large skillet over medium heat. Add the beef and cook for about 12 to 15 minutes, turning once, until browned on both sides.
2 Tablespoons vegetable oil
Add the tomatoes and garlic to the skillet, breaking up the tomatoes with a spoon. Bring the mixture to a gentle boil, then reduce the heat to low. Cover and simmer for about 1 hour and 15 minutes, spooning the sauce over the beef occasionally, until the meat is fork tender.
1 14.5 ounce can whole tomatoes, 2 cloves garlic
Stir in the water, sliced onion, and bell pepper. Bring back to a gentle boil, then reduce the heat again. Cover and simmer for another 20 to 30 minutes, until the vegetables are tender and the sauce has thickened slightly.
1 cup water, 1 large onion, 1 large bell pepper