Tempura

I had to put this one up as soon as I could because all potential options are not available year-round.

It's pretty much the soft shelled crab that I do this for- I don't spend time year-round battering and frying food.
But soft shelled crab is a once-a-year thing, and that's it.

Tempura is light-ish, as far as fried foods go, and nice appetizer idea.
Shrimp, vegetables.... and, as above, really nice with soft-shelled crab for a meal if you can get your hands on some.

Vegetable options include green beans, carrots, sweet potato, squash or zucchini, squash blossoms,  asparagus, broccoli/broccolini, sliced onions or whole green onions, eggplant...

Obviously, you'll need fry in rounds, and you certainly won't want to be making it for a huge crowd. AND, you'll want to give the oil a chance to come back up to heat between rounds as necessary. I can be personally guilty of not doing this, as I want to hurry up and get it done, but it can lead to oil-logged tempura (not quite so nice).

For me, all it needs is a squeeze of lemon and maybe a sprinkle of salt right after it's removed from the hot oil... Maybe some chili sauce if you need a little heat.
Wow. Especially that crab. So good. 
And of course, it's all best right off the heat.

Tempura Batter
(coats about 12 soft shelled crabs)

3/4 c plus 3 T (144 g) white rice flour, plus more to dredge
3/4 c (104 g) cornstarch
3/4 t (6 g) salt
1/2 t (4 g) baking soda
1 large egg, cold
1 1/2 c (360 ml) sparkling water, cold

soft shelled crabs (*gills removed by you or your fishmonger), shrimp, vegetables (onion, broccoli, zucchini, etc.) to fry
neutral vegetable oil (canola, sunflower, etc.) for frying

Whisk together the rice flour, cornstarch, salt, and baking soda in a large bowl. Refrigerate the mixture until ready to use.

When ready, heat a dutch oven over medium heat with about 2 inches or so of oil.  Dust the crab (or the onion rings, or broccoli, etc.) with rice flour and set aside.

Preheat the oven to 200-225 F (94-107 C) and place a paper towel lined sheet pan inside.
When the oil reaches 350-375 F (175-190 C) finish the tempura batter.
Whisk the egg and sparkling water together and pour into the cold flour mixture. Whisk the batter together until combined.
Quickly coat a crab with the batter and place it in the hot oil. Repeat with 1-2 more crabs, however many fit comfortably in the pot. Let the crab fry a couple minutes, until a pale golden, then flip it so the other side cooks about the same amount of time.
Remove crabs to the paper towel lined sheet pan in the oven to stay warm and drain a bit.
Repeat with the remaining crabs and/or vegetables, perhaps giving it a minute between batches to come back up to heat (too cool and your batter soaks up extra oil).
Perhaps sprinkle with salt and serve with lemon wedges, chili sauce, or as desired.