Answer:
Agreeable; satisfactory.
Explanation:
The word adequate in this context is referring to the fact that, even though it was cold, probably outside, but maybe also inside in the kitchen (with the complications that this brings while cooking and eating), the meal came out tasting good enough, probably not delicious or delightful, but, surely agreeable or satisfactory. The opposite of adequate in this context would be insipid, plain, or unsatisfactory.
