Preheat the oven to 400 F. Option to line a rimmed baking sheet with parchment paper for easy clean-up.
Add tomatoes (1 pint) and sliced shallot (1) to a large bowl, along with 2 tablespoons of pesto and 1/4 teaspoon of salt. Toss to coat the veggies in the sauce.
Spread tomatoes and shallots in a single layer on the rimmed baking sheet. Bake in preheated oven for 20 minutes.
While veggies are cooking, pat salmon (4 4-6 ounce) dry with paper towels and sprinkle with 1/2 teaspoon of remaining salt and pepper.
When the veggies are done cooking, push them towards the edges of the baking sheet with the back of a spatula, and nestle the salmon skin side down (even though we're using skinless, look for the side with grey on it) in the center of the pan. Spoon 1 tablespoon of pesto over each salmon filet, and spread it evenly over the top with the back of your measuring spoon.
Return the baking sheet to the oven and bake until the salmon is cooked through and flakes easily, should be about 18-20 minutes.
Serve salmon with shallots and tomatoes on top, and enjoy!