Preheat oven to 300°F (150°C).

Blanch almonds: Pour boiling water over almonds and let sit for 3-5 minutes.

Drain the almonds.

Cover the almonds with cold water and slip the skins off.

Dry the blanched almonds on a towel.

In a large bowl, combine blanched almonds, walnut halves, sugar, and salt.

Add beaten egg whites to the nut mixture and stir until evenly coated.

Spread the nut mixture in a single layer on a baking sheet.

Dot with butter.

Bake for 15 minutes, or until golden brown, stirring halfway through to ensure even cooking.

Let cool completely before serving.