In a large skillet, heat oil in pan over medium-high heat.
In a skillet heat oil on medium- high. Salt and pepper your cube steaks. Lightly dredge in flour then brown steaks on each side and transfer to slow cooker.
Mix cream of mushroom soup, brown gravy and water in a medium size bowl and pour over steaks. Add sliced onions, mushrooms, and garlic. Stir everything together in slow cooker.
Cook on low for 7 to 8 hours. Depending on how your slow cooker. I cook mine for 8 hours
I serve over mashed potatoes but you could serve over rice, noodles or serve next to your favorite veggie.