I haven't actually given any warm.. only either straight from the cupboard or from the fridge. I think if I did I would probably do it in a jug of hot water xx
Most of the purées say to put it in a bowl of hot water. Hope this helps x
I always heat in a bowl of water u less made fresh, microwave is risky as it can cause hot spots x
I personally use the microwave, stir really well, and first try it myself. But it's not recommended!
If I'm using ones I've frozen, I microwave for about 20 seconds and make sure all of it is warm. If it's a pouch I've bought, I squeeze some into a small tub and sit the tub in boiling water x