Prepping veg. for roasting in advance
I'm having a fairly large dinner party on Saturday night and want to do as much prep as possible ahead of time. One dish is a medley of assorted root vegetables (plus a squash) to be roasted, and I'm wondering two things:
1) how far ahead of time can I peel and chop the vegetables before roasting (I've got carrots, parsnips, celery root, onion, sweet potato and the aforementioned squash), and
2) can I actually roast them the day before and then reheat on Saturday? (I'm going to roast them with some herbs and garlic and then toss with a little reduced balsamic right before serving)
We did a roasted sweet potato and onion dish for Thanksgiving, starting it in the morning and reheating to serve. It was not very successful. It tasted okay, but the onions (red) turned a very unappetizing shade of blue and the potaotes developed a tough shell. So I wouldn't recommend roasting in advance. I'm not too sure about peeling and chopping in advance, either -- some root vegetables can darken on contact with the air. If you try it, I'd recommend either soaking them in water or tossing in oil to minimize the exposure to air.
I would peel and cut all vegetables the night before and put them either into ziploc bags or tupperware. The only vegetables that may turn color are the yams. In that case, just peel the yams and put them in water.
I think roasting about two hours prior to serving should be fine. I don't think roasted vegetables need to be served piping hot. I would not roast earlier in the day because the vegetables could turn mushy as the moisture in the vegetables tends to take over the nicely roasted (crisped) texture of the outside of the vegetable.