Another favorite from the Potatoes and Vegetables mini-book. These are a variation on mashed potatoes.
Preheat the oven to 400 degrees. Boil the potatoes in water for 10 minutes or until cooked through.
Meanwhile in the skillet, make the topping by melt 3 tablespoons of butter. Add leek and garlic and mustard and fry for 5 minutes.
Put bread crumbs in a mixing bowl with the warm topping and season to taste wiht salt and pepper.
Drain and mash the potoates, mixing in the butter, milk and cheese. Spoon mashed potatoes into oven safe dish topping with the topping.
Cook in the oven for 15 minutes or until topping is golden brown.