do you mean realistic as in good animations or realistic as in you’re literally cooking?
for literal cooking, using an oven/microwave (scripting it) would be pretty easy, however, as for cutting it may be a bit difficult. i would personally make a invisible brick that follows the player’s mouse (cutting board should be viewed top-down) and if it goes through the part fast enough it should create a thin negative part that is between the 2 points where the mouse collided and union with the other part(s) that were touched, seperating them. Once they are done cutting you could probably union all the pieces with eachother and save the object like that.
i don’t really know how someone would do this but its kinda how i think you could do them (dont know how to tackle using a frying pan, etc.)