In a large bowl, mash bread and milk together with a fork until it forms a paste. Add onion, garlic powder, egg, Worcestershire sauce, salt and pepper. Mix well.
Add ground beef and ground pork. Combine all the ingredients with your hands but do not over mix as it will toughen meat. Note: You can make the patties right away but I prefer to place mixture in the fridge for half an hour so meat is well infused with the seasonings. Cover bowl with saran wrap.
Divide the mixture into equal portions depending on how big you want your burgers and form it into a ball then flatten to about ½ inch thick.
In a deep skillet, add and spread oil over medium heat.
Fry burger about 1 ½ to 2 minutes each side to brown and get it a bit crusty. Note: Do not overcrowd burgers while frying. Do it in 2 batches.
Remove burger from pan. Do not turn off pan.
Melt butter in the same pan over low heat. Note: Pan will have brown bits sticking on the bottom, leave it there as it will add so much flavor to your burger.
Saute onion for 1 ½ minutes but not brown.
In a small bowl, dissolve Cream of Mushroom to 1 cup of water. Add to pan and stir constantly until you reach a smooth texture. Simmer for a minute or two.
Add burgers. Cover pan and simmer for about 15 to 20 minutes or until burgers are cooked over medium-low heat.
Remove burger with a slotted spoon.
Thicken mushroom gravy with flour. Stir until thick, add garlic powder. Then season with salt and pepper, if needed.
Add slice button mushrooms and continue to simmer for a minute.
Pour sauce over burgers. Garnish with green onions, if desired. Serve hot.
Serve with white rice, mashed potatoes, pasta or noodles. Enjoy!
If you prefer more gravy, use the whole can of Cream of Mushroom soup with 2 cups of water.
For moist, tender, juicy burger, do not overcooked.
If you prefer to use 100% ground beef, use 80%/20% blend or less leaner meat.