Preheat oven to 400°F.

Place baguette slices in single layer on baking sheet. Toast in oven until golden, about 8 minutes. (Can be made 4 hours ahead.)

On a separate baking sheet, spread out the grapes and drizzle with olive oil and sprinkle with salt and pepper, to taste. Roast grapes for about 15-20 min, until they burst and release some juice. Shake the tray once or twice during roasting. (Can be made 4 hours ahead. Set aside in a bowl along with any juice from the pan).

Spread blue cheese on baguette slices. Top with two or three grapes and sprinkle nuts over each (if using). Drizzle each slice with some juice from the roasted grapes.

(If serving as a first course, I like to add some lightly dressed greens such as baby kale, arugula or watercress. Just toss about 2 cups with a tablespoon of olive oil and 2 teaspoons of balsamic vinegar).