Thanks all. I figured it out in the end and made a "Fried Egg" mod as a first trial. I made the egg cookable in the frying pan, but the only problem is that the egg in the pan is a food item and doesn't have a condition, so that when you eat the egg and get the pan back, it's a brand new pan and doesn't preserve the condition of the pan before you cooked the egg. I guess I'll have to dig into the lua files and learn some more about that, which isn't so bad. One thing which is a bit of a limitation, and might need to be reviewed, is that you can cook things in ovens without cooking utensils, so that a frying pan with an egg in it is actually a food item. Also, the food item doesn't change into a different item when it is cooked, so you can't do things like take the raw egg out of the pan to make a raw egg item as opposed to taking a fried egg out of the pan to make a fried egg item. Just some things to work around I guess.