Ingredients
2 to 2 1/2 pounds beef round steak, cut into 6 pieces (about 1-inch thick)
1 large yellow onion, thinly sliced
1 large green bell pepper, thinly sliced
2 cans (14.5 ounces each) diced tomatoes, undrained
Optional but recommended: 1 teaspoon kosher salt
Optional but recommended: 1/2 teaspoon black pepper
Directions
Trim any large pieces of excess fat from the round steak, then cut the meat into 6 roughly equal portions so they fit easily in the slow cooker. Pat dry with paper towels.
Lightly season both sides of the steak pieces with the optional salt and pepper if using. This keeps the ingredient list simple while still giving the meat and gravy a little boost of flavor.
Layer the sliced onions in the bottom of a 5- to 7-quart slow cooker, spreading them out in an even bed. Scatter the sliced green bell pepper over the onions.
Lay the steak pieces on top of the onions and peppers in a single layer as much as possible. It’s okay if they overlap slightly; they’ll shrink a bit as they cook.
Pour the diced tomatoes with all their juices evenly over the steak, making sure every piece of meat is covered. Do not add extra water or broth—the tomatoes will create the gravy as they cook down.
Cover the slow cooker with the lid and cook on LOW for 7 to 8 hours, or on HIGH for 3 1/2 to 4 hours, until the steak is very tender and easily cuts with a fork. The onions and peppers should be soft and the tomato mixture thickened into a rich gravy.
Once done, taste the tomato gravy and add a pinch more salt and pepper if needed. Gently stir the onions, peppers, and tomatoes around the meat to coat everything in the sauce without breaking the steak apart too much.
Serve the swiss steak hot, spooning plenty of the thick tomato gravy, onions, and peppers over each piece of meat and over your choice of mashed potatoes, noodles, or rice.
Variations & Tips
To keep this true to its Depression era roots, the base recipe uses only four core ingredients: beef round steak, onion, green pepper, and canned diced tomatoes. Everything else is optional.
If you want a thicker, almost stew-like gravy, stir in 1 to 2 tablespoons of tomato paste during the last hour of cooking, or whisk 1 tablespoon of cornstarch with 2 tablespoons of cold water and stir it into the slow cooker for the final 20 to 30 minutes on HIGH. For extra flavor without changing the spirit of the recipe, you can add a small spoonful of Worcestershire sauce or a pinch of dried thyme or garlic powder with the tomatoes.