Melt butter in heavy pan with water. Add sugar and cook over medium heat to 294° on a candy thermometer. Pour onto a greased 9×13 baking sheet.
When spongy, after approximately 5 minutes, score with a knife into uniform squares. (If you don’t want to score, leave mixture in pan whole and break up later.)
Cover with gently melted milk chocolate. To melt chocolate, grate chocolate into bowl and place in microwave on medium/high heat for 30 seconds. Stir. Continue heating and stirring for 30 seconds until milk chocolate is not quite melted. Stir until melted. Spread melted chocolate on toffee. Cover immediately with pecans and walnuts. Refrigerate until chocolate is solid. Invert pan and break into pieces. Store in airtight containers or plastic bags.
This recipe is from The Hot Chocolate Sparrow at 5 Old Colony Way in Orleans. 508-240-2230