Step 1

Whisk cream of mushroom soup, water, and onion soup mix in a slow cooker until thoroughly combined.

Step 2

Heat vegetable oil in a large skillet over medium heat; cook and stir onion in the hot oil until browned, about 20 minutes. Transfer onion to a bowl, leaving oil in skillet.

Step 3

Brown cube steaks in the hot skillet, about 5 minutes per side. Place cube steaks into slow cooker and top with onions. Cook on Low until cube steaks are tender, 5 to 6 hours.

Step 4

Bring a large pot of lightly salted water to a boil. Cook egg noodles in the boiling water, stirring occasionally, until cooked through but firm to the bite, about 5 minutes. Drain. Serve cube steaks and mushroom gravy over egg noodles.