Place oven rack 4-5 inches from heat source and preheat broiler.
Diagonally cut the baguette into 24 slices about 1/3 inch thick. Save any extra bread for another recipe.
Brush the tuna lightly with the oil and sprinkle with salt. Broil, turning once, until opaque, about 8-10 minutes. Remove from broiler and place on cutting board; cool slightly. Leave broiler on.
Dice the tuna into 1/4 inch pieces and place in a bowl. Add in the yogurt, 1 tablespoon of parsley, olives, capers, chives, and lemon juice and mix well.
Place the baguette under the broiler and toast lightly on both sides, about 1-2 minutes. Place 1 tablespoon of tuna onto each baguette and top with 1-2 slices of pepper. Evenly sprinkle each with remaining parsley.