PreparationMake tuna salad: Whisk together mayonnaise and lemon juice in a large bowl. Add remaining salad ingredients and stir together gently. Season with salt and pepper. Assemble sandwiches: Cut baguette into 4 equal lengths and halve each piece horizontally. Brush cut sides with oil and season with salt and pepper. Make sandwiches with baguette, lettuce, and tuna salad.
PreparationMake tuna salad: Whisk together mayonnaise and lemon juice in a large bowl. Add remaining salad ingredients and stir together gently. Season with salt and pepper. Assemble sandwiches: Cut baguette into 4 equal lengths and halve each piece horizontally. Brush cut sides with oil and season with salt and pepper. Make sandwiches with baguette, lettuce, and tuna salad.