Preheat oven to 300. Stir together flour, sugar, and salt in a large bowl. In a heavy bottomed saucepan, melt chocolate and butter together over low heat, stirring often. Lightly beat eggs with milk and vanilla. Add egg mixture, melted chocolate and butter mixture to flour. Stir until smooth. Stir in walnuts and cherries along with any cherry juice. Pour into a large greased 9 inch square baking pan. Bake about 1 hour and 5 minutes. Cool on a rack, then cut into squares and serve plain or with vanilla ice cream or barely sweetened lightly beaten cream.
