As long as you don't complete the full 2x dishes (only do a few of them) you can do 2x completes the following year. I'm not absolutely sure if there is a restriction on this but I suppose that if you do, for example, the first and second generation foods and start doing the first generation ones again and don't finish, the general contactor will move to the second phase and as soon as it completes it once again you will have won the achievements and you will not be able to do the foods 2x in a row.