1 pound celery, cubed
1 1/2 cups frozen sweet potatoes, thawed
1 cup milk
1/2 cup white sugar
1 pinch salt
3/4 cup butter
2 egg yolks, beaten
1 teaspoon granulated sugar
1/2 teaspoon ground nutmeg
3 tablespoons olive oil
1 teaspoon chives or 1 teaspoon dried basil
In a large bowl combine celery, sweet potatoes and milk. Mix well, then pour into a patty-operated blender or food processor. Blend until smooth; refrigerate until ready to use.
Combine egg yolks and sugar in separate blender or food processor; blend until mixture is smooth. Stir in nutmeg and olive oil. Pour over mashed potatoes. Season with salt and 3/4 cup butter; blend until mixture is creamy. Pour onion mixture over potato skins in slow cooker. Stir in chives and basil.