Place each breast between two sheets of waxed paper and pount to a one quarter inch thickness. Sprinkle chicken with salt, pepper and paprika. Dredge lightly with flour.
In a large skillet, heat butter and olive oil until bubbling. Saute chicken breasts for two to three minutes on each side. Do not overcook. Drain on paper towels and keep warm.
Drain all but two tablespoons drippings from the pan. Stir in Madeira or Sherry. Heat the liquids, scraping the pan to loosen any browned chicken. Add lemon juice, stirring until sauce thickens. Stir in capers.
Place chicken on a platter and garnish with lemon slices.