1 tbsp.olive oil plus additional for brushing
3/4 cup sliced shallots
1 garlic clove, thinly sliced
1/4 tsp. coarse kosher salt plus additional for seasoning
1/4 tsp. chopped fresh thyme plus additional for seasoning
1/8 tsp. ground black pepper plus additional for seasoning
1 cup fresh blueberries
1/4 cup water
1 tbsp. white vinegar
1 tbsp. honey
4 7-ounce salmon steaks or fillets with skin (each about 3/4 inch thick)
3 tablespoons thinly sliced fresh mint, divided (optional)
Heat 1 tablespoon oil in large skillet over medium heat. Add shallots; sauté until softened, about 5 minutes. Add garlic, 1/4 teaspoon coarse salt, 1/4 teaspoon thyme, and 1/8 teaspoon black pepper. Stir until fragrant, about 30 seconds. Add blueberries, 1/4 cup water, honey, and vinegar. Stir to blend. Mash berries with potato masher or back of fork and cook until sauce thickens, stirring often, 3 to 4 minutes. Season with freshly ground black pepper. Remove from heat. Can let stand at room temperature for a little while. Rewarm before using.
Prepare barbecue (medium-high direct heat). Brush salmon on both sides with oil; sprinkle with coarse salt, thyme, and black pepper.
Grill salmon until just opaque in center, 4 to 5 minutes per side. Transfer to plates. Stir 2 tablespoons sliced mint into warm blueberry sauce. Spoon sauce over salmon and sprinkle with remaining 1 tablespoon mint. Serve immediately.