3 cups cubed cooked roast beef
2 cups cooked diced vegetables
2 cups gravy
1/4 teaspoon each salt and pepper
Biscuit Topping:
2/3 cups butter softened
1/2 cup boiling water
1 egg yolk
1 cup whole wheat flour
1 cup all-purpose flour
1 cup shredded Cheddar cheese
2 teaspoons baking powder
1/2 teaspoon salt

Biscuit Topping: In large bowl, stir butter with boiling water until butter is melted. Let cool.
Meanwhile, in 9-inch (2.5 L) square metal cake pan, combine roast beef, vegetables, gravy, salt and pepper. Set aside.
Stir egg yolk into butter mixture. In separate bowl, whisk together whole wheat and all-purpose flours, cheese, baking powder and salt. Add to butter mixture. Mix with fork until dough clumps together. On floured surface and with floured hands, knead dough about 3 times until smooth with ragged edges. Pat dough into 8-inch (20 cm) square; cut into 9 squares. Fit squares, side by side, over filling.
Bake in centre of 400°F (200°C) oven until filling is bubbly and biscuits are no longer doughy underneath, about 40 minutes