Prepare a large slow cooker with cooking spray. Sprinkle onions all over the bottom. Next sprinkle celery, then carrots and last the steak.
Next, grab a large bowl and dump in your canned tomatoes. If you prefer a thicker stew, use the smaller, 14 oz. size. If you like you stew with a thinner sauce, use the larger 28 oz. size.
While your bowl is still in front of you add broth, mushrooms, tomato paste, and all of the spices. Stir until blended. Pour on top of the meat in your slow cooker and do not stir the mixture around at all. While pouring make sure the mixture goes everywhere! As evenly as possible. Again, do not stir the contents of your slow cooker.
Cook on low for 7-8 hours or high for 3 1/2 to 4. Remove lid and stir. Taste the gravy and decide if you want to add any more seasoning or my son's favorite, hot sauce to satisfy your personal taste! Serve with bread for dipping into the gravy or a side salad if desired. Enjoy!