I introduced kitchen items when DS was very little. Initially just the safe items I already had in the kitchen rather than buying a set of toys. I would lay him on a soft blanket on the kitchen floor whilst I washed up or cleaned and just hand him one safe item.
I describe it here and how it built up over time if you are interested
Cycle of Activity-Help Build Independent Playtime(it's reply 2 but the whole thread is interesting and useful)
We had a big set of plastic cookie cutters from a very early age, didn't cut cookies with them, just looked at the shapes and colours, picked them up, dropped them, put them all in a tub, emptied it out etc. Much later these cookie cutters were used for cutting play doh, and obviously I gave them a good wash before they were used for cooking real cookies.
I also love love love a toy kitchen, whether it is a re-purposed cupboard or side board or, a cardboard box with a hob drawn on the top, a plastic kitchen set or a beautifully crafted wooden kitchen set, they are ALL great for young toddlers, as soon as they are cruising and toddling they can stand at a play cooker. I think we got ours when DS was 1yo, he still plays with it now at 4yo (great value for money). As soon as a LO can sit up they can play with cups and saucepans (real or toy) and will probably love exploring the shape, sound, bashability etc.
Play food is another love, again it can be plastic, wooden, knitted, whatever. Recycled food packing is great. DS learned the names of many fruit and vegetables from toy food and food cartons. This sort of thing is great from 6 months so long as you check the size and suitability of each piece so she can't choke on it.
And as MJ&N has said, real tools when older and joining in real cooking are great. I have a child safe knife for DS to help me chop vegetables, he loves making real dinner.