with salt and pepper until everything is evenly coated. place in the oven at the same time the tarts go in. they will take the same amount of time: about 20-25 minutes. while the grapes are in the oven, take the stems off the spinach leaves, wash and pat dry. place in a large bowl. when grapes come out, let them cool on the baking sheet for about 5 minutes and then toss with spinach leaves. the coating on the grapes will create a dressing for the salad. 