Slice 2 sweet potatoes into 1/8-inch-thick rounds. Brush with olive oil and season with salt and pepper. Bake at 425 degrees F until crisp, about 15 minutes, then cool on a rack. Mix 2 tablespoons chopped chives with 1/4 cup creme fraiche; dollop on the potatoes and top with caviar.
Photograph by Levi Brown