Potatoes are most easily cooked in a microwave - just poke a few holes with a fork and nuke for 5 minutes on high, maybe another minute or two if the potatoes are very large. The best way to fry them is in an air fryer. We cut yesterdays cooked potatoes into 1/4 inch thick rounds and spray with a little olive oil. We always eat the skins and all - I read someplace there are lots of nutrients in or near the skin. Salsa is a good alternative to ketchup for more flavor and less calories. Sweet potatoes and butternut squash are good alternatives to avoid the monotony.