Tuna and Fava Crostini

Preheat oven to 350°F. Arrange baguette slices in single layer on baking sheet; brush slices with 3 tablespoons oil. Bake until bread is crisp and golden, about 15 minutes. Set aside.

Bring medium saucepan of water to boil. Shell fava beans, then drop beans into boiling water and cook 1 minute. Drain. Slip beans out of skins. Place beans in small bowl; add remaining 1 tablespoon oil and toss to coat.

Combine tuna with its oil, minced red onion, chopped parsley, and lemon juice in small bowl. Using fork, mash tuna mixture to coarse paste. Season mixture to taste with salt and pepper.

Baguette slices, fava beans, and tuna mixture can be prepared 4 hours ahead. Let baguette slices stand at room temperature. Cover and refrigerate fava beans and tuna mixture separately.

Divide tuna mixture among baguette slices. Top with fava beans and garnish each with 1 parsley leaf.