Salmon and Blueberry Salad with Red Onion Vinaigrette - Blueberries

Ingredients

• 1 medium-sized red onion, thinly sliced in half rings
• 1/4 cup Regina red wine vinegar
• 1 teaspoon sugar
• 1 teaspoon salt, divided
• 1/4 teaspoon ground black pepper, divided
• 3 tablespoons olive oil, divided
• 1-1/2 pounds salmon fillet, cut crosswise in 4 portions
• 6 cups lettuce leaves in bite-sized pieces
• 1 cup fresh blueberries