1/4 c. each butter or olive oil
2 lb. each sweet potatoes and russet potatoes, peeled and cut into 1-inch chunk
1 lg. onion, cut into eights
8 cloves garlic, cut into halves
1/2 c. unsalted hazelnuts, coarsely chopped

Put butter, oil, sweet potatoes, russet potatoes, onion and garlic in a 10 x 15 inch baking pan at least 2 inches deep. Spread vegetables evenly. Bake on bottom rack at 475 degrees for 30 minutes; stir with wide spatula after 15 minutes. Vegetables near rim of pan begin to brown quickly. If made ahead, remove from oven and let stand, uncovered, up to 4 hours.

Mix nuts with potatoes; continue to bake and stir occasionally until potatoes are very tender when pierced and are tinged with brown, about 15 minutes (20 minutes if cooled). Makes 12 servings. For less fat use less oil or fat.