For 'roast' potatoes I first cook them in the microwave and then brown them in the frying pan (bacon fat or olive oil).
Hardly ever use my 'proper oven'....damned expensive, mostly the microwave or the 'health grill' to get rid of excess fat rather than frying.
I only cook for me and my boy, but we eat well, though frugally, and virtually all fresh ingredients.
I feed both of us a good varied and healthy diet for less than 40 quid a week.