cooking is really tough and really underpiad, engineering is well paid and in demand (do that one) and computer science is also pretty well paid (if you make it big, like Bill Gates; then very big) but is quite competitive I think.
Your best shot is to speak to a careers advisor (may I sugggest connexions) as they will give you nearly 100% acurate information (but don't believe every single word tey say, you need to look into it too from respected sources)
best of luck to you; I would do engineering and cooking in my spare time and maybe set up a restaurant when you retire and hopefully you will get luucky and become a rich chef and owner of a successful branch of restaurants called "Mr. Cheese"...Just an idea
anyway, good luck and remember to research your future in great depth!!!
also check out science and maths.org and thestudentroom.org