until liquid is completely absorbed, about 1 minute. Repeat with remaining stock, stirring continuously, adding 1/2 cup at a time. Add more stock only after previous addition has been absorbed. Continue to cook, stirring and adding hot stock, until rice is creamy and just tender, 20 to 25 minutes. Remove from heat and stir in remaining butter, cheeses, and pepper. Serve immediately. Makes 4 to 6 servings. BASIC RISOTTO: Use the same recipe except increase the butter to 1/4 pound, increase the Parmesan cheese to 6 tablespoons and omit the other three cheeses [COOKS; APRIL 1989]