Preheat the oven to 425 degrees F. Line a rimmed baking sheet with parchment paper or foil.
Place the salmon, skin side down, on the baking sheet.
Arrange the vegetables alongside the salmon around the edges of the baking sheet. Drizzle the vegetables with olive oil. Sprinkle the salmon and vegetables with salt and pepper. Cover the fish and vegetables with another piece of parchment paper or foil. Bake for 10 minutes.
Meanwhile in a small bowl, combine the brown sugar and stone ground mustard. Remove the salmon from the oven and remove the top piece of parchment paper. Spread the brown sugar mixture over the top of the salmon. Place the pan back in the oven and bake until the thickest part reaches 135 degrees F, about 15 minutes.