There are 10 levels in this skill. The cooking skill is a skill that almost all sims we have some levels in. Sims do have to eat. It is one of the fastest and easiest skills to get. The lot trait Homey will give your sim a +50% skill gain boost.
To start, get an oven, a fridge, and a counter or a grill and counter, or buy the cooking books from a bookshelf or watch the cooking channel.
I got this achievement by having my sim join the chef career and cooking several meals a day. Within two hours my sim had this skill maxed out. I also had my sim watch the cooking channel when their entertainment level low.