In a large bowl, use your hands to blend together the beef, turkey, bread crumbs, tomato paste, Worcestershire sauce, mustard, onion powder, garlic powder, salt and pepper until well combined. Divide the beef mixture into equal size portions and form into patties about 1/2 inch thick.
Heat 1tsp EVOO/avocado oil in a skillet over high heat. Add the steaks and cook the first side for 1 minute or until browned, then gently flip and brown the other side (they will still be raw inside). Remove onto plate.
If skillet is looking dry, add a touch more oil. Add onion and garlic and cook for 2 minutes until onions are a bit translucent.
Add the mushrooms into the skillet and cook for 2-3 minutes until golden.
Turn heat down to medium. Add butter. Once melted, add cornstarch and cook for 30 seconds, stirring constantly.
Gradually add in beef broth, stirring as you go. Once mostly lump free, whisk in remaining ingredients
Add steaks along with the juices back into the pan. Cook for 5 – 7 minutes, or until gravy is thickened, stirring occasionally around the steaks. If the gravy thickens too quickly, add water.
Remove steaks onto a plate. Taste gravy and adjust salt and pepper to taste.