01 -
Mix flour, garlic powder, onion powder, paprika, salt, and pepper on a plate. Press each steak into the mixture to coat both sides. Shake off excess.
02 -
Heat oil in a large skillet over medium-high heat. Brown the steaks for 60 to 90 seconds per side until lightly golden. Transfer to the slow cooker.
03 -
In the slow cooker insert, whisk together the au jus mix, French onion soup, beef broth, and Worcestershire sauce until smooth. Add the sliced onion and mushrooms. Nestle the seared steaks into the liquid.
04 -
Cover and cook on low for 6 to 7 hours, until the steaks are fork-tender.
05 -
Whisk cornstarch and cold water in a small bowl. Pour into the slow cooker, gently moving steaks aside so the slurry mixes in. Cover, turn to high, and cook for 20 to 30 minutes until the gravy thickens.
06 -
Spoon gravy over the steaks and serve with mashed potatoes, egg noodles, or rice.