Combine all the ingredients for the vinaigrette in a medium bowl. Let sit at room temperature for at least 30 minutes. If made in advance, store in fridge and remove and let come to room temperature and mix well before serving.
Heat the grill to medium-high heat.
Brush the salmon on both sides with oil and season with salt and pepper. Grill skin side down for 3-4 minutes (this was enough for me). Turn and move to a cooler part of the grill to cook for 3-4 more minutes.
Serve the salmon with the vinaigrette over the top.
Notes
Note - my salmon was cooked in 3-4 minutes on one side. I did not need to flip it. A variety of heirloom tomatoes makes a colorful vinaigrette. If you need to make it ahead of time you can store it in the fridge, but I wouldn't keep it in the fridge for long, tomatoes get mealy when they are refrigerated.