Healthy and easy to make, these crostini will be the hit of the party. Toast the bread and make the lima-bean mixture in the morning. Assemble the crostini at the party.
Preheat oven to 350 degrees. Place baguette slices on a rimmed baking sheet and brush with 2 tablespoons oil; season with salt and pepper. Bake until golden, 10 minutes. Rub warm slices with garlic cloves; let cool.
Meanwhile, place rosemary in a small saucepan of salted water and bring to a boil. Add lima beans and cook until tender, 7 minutes. Drain and transfer to a cutting board. Strip leaves from rosemary sprigs; roughly chop beans and rosemary and place in a medium bowl. Add 2 tablespoons each oil and lemon juice; season with salt and pepper.
Season ricotta with salt and pepper, then spread on crostini; top with lima-bean mixture.
Bring It! To bring to a potluck, toast the bread and make the lima-bean mixture in the morning. Assemble the crostini at the party.