What's your current favorite fruit or vegetable side dish?

Southern collard green with ham hock.

Fava beans are just coming into season. They are damn hard work but well worth it.

Fresh asparagus spears with hollandaise.

Made this a couple of weeks ago: http://smittenkitchen.com/blog/2011/05/spring-salad-with-new-potatoes/. Super tasty and spring-y!

I recommend a rice pilaf like this one, http://cooking.nytimes.com/recipes/12792-rice-pilaf-with-carrots-and-parsley

This time of year, hands down it's Ragout of Peas & Artichokes. https://food52.com/recipes/4070-ragout-of-peas-and-artichokes

I love french beans sauteed with fresh or frozen coconut with some mustard seeds tempered in oil, pinch of turmeric, dry red chillis, tbsp of moong dal and curry leaves, salt. Its called beans poriyal. Easy and quick to make and tasty at room temperature. You can remove the chillis and curry leaves once it is cooked.

So many great ideas for me to work into our regular repertoire well beyond the potluck -- thanks all!

Black bean and corn salad. So easy. Depending on how many you want to serve, I use one can of black beans, a can of corn (you can also use frozen corn), one green pepper diced, one stalk of celery chopped, Good Season's Italian Dressing, salt and pepper. Drain and rinse the vegetables. Mix everything together and add the dressing 'to taste'. Have made this many times for parties and it is gone in a blink. Good luck!

Whole Green beans, lightly blanched...chilled and dressed with a vinegrete and Parmesan cheese before serving.
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CousCous with parsley, and peas or carrots...dressed with a lemon olive oil dressing. Or asparagus and cherry tomatoes.
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A rice salad with mandarin orange slices is one that stands up to travel and room temp.

I'm loving Ottolenghi's butternut squash with sweet spices and lime from Plenty. It's really at it's best at room temp. You may want to adjust the spices for your audience though. Not sure how many kids love cardamom.

My other addiction is roasted yellow beats, turnips, New potatoes with preserved lemons. I usually cook chicken thighs on top of them after browning them, but they'd be good on their own. Salt, pepper and olive oil is all I use.

How about sweet and sour caponata?

I am completely in love with the Gjelina roasted yam dish. I use Garnet potatoes. Every time I serve this the crowd goes gaga. http://cooking.nytimes.com/recipes/1017992-gjelinas-roasted-yams

Cauliflower cut into florets or sliced, roasted at high heat with oil and salt (450C+), tossed with any number of seasoning mixtures near the end or after it's done (parsley+garlic+fennel seeds+chopped olives+lemon, ras-el-hanout, preserved lemons+harissa for example). Ottolenghi's Plenty also has a great cauliflower dish that's intended to be room temp with saffron, onions, raisins, and olives.
It's mango season (ok, in South/Central America, but still, this is when they're best in N. American markets too) -- mango, cucumber, jicama, pineapple and other raw things that are good with Tajín? Or mango + sticky rice if something more dessert-like works.

Hey! My favorite thing right now is new potatoes, boiled, with halved, steamed green beans. Douse with butter that's been heated with minced garlic. Stir in chopped dill, parsley, lemon zest, lemon juice to taste. It's pretty salad-y, but I don't really count it as a "salad."

This is one of our favorites and is wonderful served at room temperature:
https://food52.com/recipes/25622-batsaria-phyllo-less-spanakopita

Ah, that's a tough one, this time of year, given how little there is locally available, other than beets, lettuces and greens . . . . . I imagine your choices are even more limited. The fennel looks great here now, so I'd consider making my Florentine Fennel. For your crowd I might dial back on the cheese, resisting the temptation to throw on Asiago and Pecorino Romano -- though my son at that age (the same son who requests this dish at Thanksgiving and every other occasion possible) actually liked the stronger cheeses even then.
Wondering if you could get away with this, even though it's technically a salad: cucumbers, cut/seeds scraped out/drained/patted dry/ dressed in a light sesame oil and cider vinegar dressing (+ pinches of sugar and salt + ground pepper) with a few bits of julienned carrots and blanched snow peas added for color, with roasted sesame seeds generously sprinkled on? My boys loved that! Or if you can get them, snap peas blanched and lightly tossed with the same dressing and sesame seeds. Or blanched and tossed with a cider honey mustard ;o)