See notes section below for Slow Cooker instructions.
Seasoning Prep: Combine the meat seasoning mix and set aside.
Gravy Prep: Combine the cornstarch and cold water in a medium bowl and whisk until incorporated and smooth. Add 1 cup chicken broth, 1 cup beef broth, 1 beef bouillon, 1 tsp onion powder, ½ tsp garlic powder and 1 ½ tsp Worcestershire sauce. Whisk to combine and set aside.
Meat Prep: Place saran wrap over each cube steak and use the rough end of a meat tenderizer to pound it thin, about ½ inch thick or so. This really makes a nice difference in the consistency of the meat even though cube steak has already been tenderized.
Rub seasoning mix on each side of the steak, then rub with flour.
Heat 2 TBS olive oil in a large skillet over medium-high heat. Sear 2 steaks at a time for about 4-5 minutes per side. (Add a splash more olive oil if needed and adjust heat up or down slightly as needed as the steaks cook.) Set steaks on a plate to rest.
Leave the meat flecks in the pan, this is called “fond” and it will add flavor to the gravy. If you have any black/burnt areas, use a damp paper towel to carefully clean that out.
Melt 2 TBS butter over medium heat and use a silicone spatula to ‘clean’ the bottom of the pan. Add the onions and toss to coat. Cook the onions for 15-25 minutes, until desired consistency is obtained. I like mine very soft and reduced, almost caramelized. Be sure to stir them often as they cook.
Add the liquid gravy mixture and use a silicone spatula to clean the bottom and sides of the pan once again. Bring to a boil, then reduce to a simmer.
Add the steaks and any juices back to the pan and spoon some gravy on the top of each steak. Simmer with the lid partially covered for 5 minutes or so, until the gravy is thickened and the meat is cooked to your liking.
Optional: Remove from heat and melt 2 Tablespoons cold butter at the end for a silky, velvety finish. This is a technique that chefs use called “monter au beurre”.