Rehydrate the TVP with boiling water. Let sit for a few minutes so the TVP soaks up the water.
Meanwhile, chop onions and carrots and mince garlic. Add to a pan, with a splash of water, over medium heat and cook until onions are translucent and carrots are tender.
Add cooked veg to TVP and add in the rest of the hamburger steak ingredients. Mix until well combined and let the mixture sit for 10 minutes, during which time it should thicken and hold together. If the mixture is still loose after 10 minutes, add in more breadcrumbs, 1 tbsp at a time, until the mixture comes together.
Scoop about 1/4 cup of the mixture and toss back and forth between your hands a few times to get out any air bubbles. Then form into a patty and repeat with the remaining mixture.
Grease a pan over medium heat and cook patties for 1-2 minutes on each side, until browned.
When all the patties are cooked, remove from the pan. Add sauce mixture to pan and heat, letting some of the sauce evaporate if it is too watery. Add patties back into pan and carefully coat with sauce. Remove from heat and serve immediately.