Mix flour, garlic salt, and black pepper together in a shallow dish.
Gently press beef cubes into the flour mixture to coat evenly.
Heat olive oil in a skillet over medium heat; cook and stir beef in batches in hot oil until browned completely, about 5 minutes per batch. Remove browned beef with a slotted spoon to a bowl until all beef is browned.
Stir water and beef stew seasoning mix together in a slow cooker until the seasoning is dissolved into the liquid. Add browned beef, potatoes, onion, diced tomatoes with green chile peppers, and hot pepper sauce.
Cook on High, 3 1/2 to 4 1/2 hours. Add frozen corn and continue cooking until the corn is hot, about 30 minutes more.