In a large mixing bowl combine hot roll mix and potato flakes. In a saucepan heat yogurt and water until warm (120 degree F to 130 degree F). Mixture may appear curdled. Stir yogurt mixture and egg into flour mixture. Turn dough out onto a lightly floured surface. Knead about 5 minutes or until smooth and elastic. Shape dough into a ball. Cover and let rest 5 minutes.
Meanwhile, in a large skillet cook ground lamb or beef until brown. Drain fat. Stir in 1-1/4 cups of the cheese, the peas and carrots, tomato, green onion, Italian seasoning, and pepper.
Grease an 11- to 13-inch pizza pan. On a lightly floured surface, roll two-thirds of the dough into a circle 1 inch larger than pizza pan. Transfer dough to pan. Build up edges slightly. Do not let rise. Spread meat mixture over crust. Sprinkle with remaining cheese.
Roll out remaining dough into a circle that matches the diameter of your pizza pan; cut into 1/2-inch wide strips. Weave strips over filling to make a lattice-top crust. Trim ends of strips even with edge of pan. Pinch ends of strips to bottom dough to seal. Brush dough with milk.
Bake in a 400 degree F oven for 30 to 35 minutes or until cheese melts and pizza is heated through. If necessary to prevent overbrowning, cover pizza with foil after 20 minutes. Makes 6 servings.