When it comes to food products I have always found honesty to be the best way to go. don't go into detail (at two and a half your shouldn't have to worry about too much detail anyway - at least I haven't had to with Jelly), but rather let them make their own associations. If they ask a question you aren't sure how to answer - throw it back at them and ask what they think and go from there. Also keep it light hearted. My daughter(2and a half yrs old) loves chickens (both to eat and as animals). her aunty Bev has some, and when Jelly sees or talks about them she always says "Yummmy chickens!" - and she knows she eats chicken as well as plays with them - but as yet I don't think she has even considered how or even that they do go from the garden onto her dinner plate, they are called the same thing but still seperate in her mind.