Place the flour, cornstarch, garlic salt, salt, Italian seasoning and pepper in a bowl and mix.
Crack the eggs into a second bowl and use a whisk or a fork to whisk them until they are lemony in color.
Dip each cube steak into the egg first and then coat each side with the flour mixture. Continue with each cube steak, moving them to a plate or a cutting board to rest. Allow the cube steaks to rest with the flour mixture on them for 10 minutes.
Heat the oil in a skillet over medium-high heat until it starts to ripple.
Place the prepared cube steaks into the hot oil and brown it on each side. This should only take a minute or so on each side.
Once the beef is browned, place each piece of steak in a slow cooker.
Pour the spaghetti sauce over the beef. Cover the slow cooker and cook on high for 4 hours (or on low for 6-7 hours).
The last 5 minutes of cooking, remove the lid and place the 4 slices of cheese over the cube steaks. Recover the slow cooker and let it rest for 3-5 minutes or until the cheese is melted.
Serve the steaks over spaghetti or spaghetti squash with additional sauce and a sprinkling of fresh parsley if desired.
Notes
The calories shown are based on the recipe serving 6 (no pasta or squash included). Since different brands of ingredients have different nutritional information, the calories shown are just an estimate. **We are not dietitians and recommend you seek a nutritionist for exact nutritional information.**