Heat a large skillet on medium to high heat.

Peel and grate an onion using a cheese grater or chop it in a handy chopper until it almost turns to puree.

To make the patties, in a bowl, mix the pureed onion, ground beef, oat flour, coconut aminos, and tomato paste.

Form the meat mixture into 12 tightly packed patties and salt and pepper both sides.

Once the skillet is hot, add the oil and sear both sides of the patties. Remove from skillet.

To make the sauce, chop the second onion and slice the mushrooms.

Crush the garlic and add it along with the onion and mushrooms to the skillet and sauté until the onion is beginning to turn translucent. If the skillet is getting dry, add more oil.

Add the broth, apple cider vinegar, tomato paste, salt, and the spices to the sautéed vegetables and stir.

Place the patties back in the skillet, and simmer on low to medium heat until the sauce has reduced to your preferred consistency.