1 cup butter or margarine 1 cup granulated sugar 1/3 cup packed brown sugar 2 tablespoons water 1 cup sliced unblanched almonds 1/2 teaspoon baking soda 1/3 cup semisweet chocolate pieces 1/2 cup pistachios (optional)
Grease 13x9x2" baking pan; set aside. In 3-quart saucepan melt butter. Add sugars and water and mix well. Bring to boil, stirring constantly. Place candy thermometer in syrup and when it reaches 260 degrees F, stir in almonds. Boil to 300 degrees F (hard-crack stage), stirring occasionally. Remove from heat; stir in soda.
Working rapidly, pour candy into greased pan, top with chocolate pieces and let stand a few minutes until melted. Spread chocolate evenly, then sprinkle with Pistachios. Cool in pan on rack.
To serve, break in pieces. Store airtight with waxed paper between layers in cool, dry place 4 weeks.