Definitely a cucumber salad. I slice them thin and dress with Greek yogurt, lemon juice, dill, and a dash of garlic powder. You can add red onions or bell peppers for color.

Grilled zucchini and yellow squash is delicious too, with some shredded Parmesan on top.

Or tri color pasta tossed in lemon butter with plenty of fresh ground pepper.

I know it’s not as summery, but I love seared salmon with braised lentils. Something like the below recipe;

https://www.williams-sonoma.com/m/recipe/braised-lentils.amp.html

Ina garten’s roasted vegetable orzo

It's warm out now, so could you may just do cold dishes?

orzo with roasted tomatoes, garlic, spinach, olive oil, lemon zest, herbs, and parm

chilled roasted asparagus

a simple salad tossed with vinaigrette

vinaigrette potato salad with roasted potatoes

etc...

I made an orzo with lemon/asparagus and it was perfect with the salmon. I made it an hour ahead of time and it stayed warm. Thank you for the suggestions

This orzo salad without the shrimp: https://www.foodnetwork.com/recipes/food-network-kitchen/orzo-salad-with-shrimp-and-feta-recipe-2042870

I’d roast asparagus on the same pan alongside the salmon, and either make a lemon orzo on stovetop (you can make ahead and serve it room temp) or roast baby potatoes (with evoo, garlic and lemon) in the oven on another pan, just pop them in 20 min before you start cooking the salmon.

I'd like to make something ahead of time that I can warm in the oven to go with Salmon. I'm having a dinner party for 12 and don't want to have to do a lot of cooking when the guests arrive. Any ideas?