Position a rack in the upper third of the oven and heat the oven to 180c.

Simmer the cider in a small saucepan over medium heat until reduced to 1/2 cup, about 5 minutes. Add the raisins and set aside to cool.

Combine the apple, grapes, parsley, and scallion in a medium bowl. Add the cooled cider mixture and toss. Season to taste with salt and pepper.

Arrange the bread slices on a rimmed baking sheet and brush the tops with olive oil. Bake until crisp and pale golden, about 10 minutes.

In a medium bowl, toss the collard greens with the 1 Tbs. olive oil, the vinegar, and salt and pepper to taste.

Spread the cheese on the crostini. Top with the greens, pressing them gently so they’ll stick to the cheese.

Using a slotted spoon, top with the relish.

Serve immediately.