Mince the chicken and ham finely, pound with the other filling ingredients until smooth, seasoning to taste, then rub through a fine sieve. Roll out the nouille paste as thinly as possible, cut out some rounds of about 1½ in. diameter. Place a small teaspoonful of the filling in the centre of half of the rounds, wet the edges. Cover with the remaining rounds, and press the edges well together. Put into rapidly-boiling salted water, boil for about 20 min. from the time the water re-boils, then drain well. Place in layers in a well-buttered dish, coating each layer with tomato sauce and a good sprinkling of cheese. Cover the top layer thickly with sauce, sprinkle well with brown breadcrumbs, and add a few small pieces of butter. Bake in a hot oven (425° F., Gas 7) or put under the grill for about 10 min., then serve hot.