This is an old Weight Watcher's recipe my mom has been making since the late 70's. We both still make it to this day. The recipe contains no added fat, but you would never know it. Goes great served over rice or egg noodles.
Season the meat with salt and pepper to taste. Weigh out 4 oz/125 gm of meat and shape into a pattie. Do this with the remaining meat. Place patties on a platter, cover with plastic wrap/cling film and set aside.
Pour water into a large fry pan/skillet over medium high heat. Add stock cubes (use beef cubes for veal, chicken cubes for turkey), onions and mushrooms. Bring to a boil and then lower heat to simmer. Cook until onions are just about cooked. You may need to add more water as the veggies cook as you want to have about 2 cups worth of gravy at the end.
Gently place the burgers in the pan with the veggies and poach for about 5-7 minutes on each side, pressing down with a spatula to flatten a bit. Cook until juices run clear. Remove the cooked burgers to a plate and keep warm. Return sauce to a boil and add more water if necessary.
Put cold water into a small cup or bowl and stir in cornstarch with a fork or whisk. Slowly pour into the sauce in the pan and thicken.
Place rice or noodles on plate, place two burgers on top, and pour gravy over burgers.