Cut up beef into bite sized pieces and place in a slow cooker.

In a small bowl, combine water, beef bouillon cubes, catsup, minced garlic and salt. Pour over the beef.

Cook on low for 8 hours.

One hour before cooking is finished cook the onion and mushrooms in butter or olive oil on the stovetop until softened about 5-10 minutes. Add to the slow cooker for the final hour of cooking.

Once beef is cooked, cook egg noodles according to the package directions.

Using a ladle, remove 2 cups of beef broth to a heat safe bowl or mug and add the flour. Use a fork to whisk it until combined. Pour the flour mixture back into the slow cooker and stir until the sauce is thickened.

Serve immediately over the hot egg noodles.