How to Make It
Heat oven to 400° F.
Line a rimmed baking sheet with foil or parchment. Place the salmon on the baking sheet and season it with ½ teaspoon salt and ¼ teaspoon pepper. Roast until the salmon is opaque throughout, 12 to 15 minutes. Set aside and let cool.
While the salmon cooks, bring a large pot of water to a boil. Put a large platter next to the stovetop.
While you wait for the water to boil, cut the ends off the green beans and shuck the corn.
Add the green beans to the boiling water and cook until bright green and just tender, about 4 minutes. Remove the green beans with a slotted spoon and place in a stripe on the platter.
Add the corn to the pot and cook until just tender, 3 to 4 minutes. Transfer the corn to a cutting board and use a serrated knife to cut the kernels off the cob. Place the corn in a stripe on the platter alongside the beans.
Halve the tomatoes and cut up the cucumber and any other vegetables that you are using. Place each in a stripe on the platter.
Using a fork, flake the salmon into pieces and arrange it on the platter in one final stripe. Serve with the vinaigrette.