Scalloped Potatoes With Ham with butter

3 cups leeks , washed very well and then thinly sliced (about 6 large, white and pale green parts only) 1/2 cup unsalted butter 3 1/2 cups whole milk 6[...]

1 cup chicken stock 1 ounce dried porcini mushrooms , rinsed 1/3 cup approx. butter 1 garlic clove , peeled, cut in half 3 leeks , white & pale green parts,[...]