Melt chocolate and butter together in microwave or double boiler or straight in pot over stove, whichever is easy for you

Stir in flour a little at a time until mixed

Beat egg whites until stiff

Preheat oven to 350 F and grease a rectangular pan with butter lightly

Fold in beaten egg whites into chocolate mixture until combined well

Pour in melted butter mixture, mix well

Pour 1/2 batter into pan, sprinkle with chopped walnut then pout the rest of the batter and sprinkle top with more walnut

Bake for 25 minutes or until knife comes out clean

Great to be served warm or room temperature

Enjoy~