Definitely take this opportunity for him to help with cooking. He can still peel potatoes, carrots, chop cabbage, stir meat etc. etc. all within his capabilities. He can make his own tea and coffee, you are a wife not a waitress service.
However, having had major abdominal surgery (a friend called it a "guts out" op (!) the best thing he can do is walk! With coaxing from my husband, I could walk 2 miles within 3 weeks of my op, and felt better after each walk as any fluid/puffiness goes down when you walk, as it gets the circulation going. So why don't you BOTH go for a walk together?