For the Sauce; in a heavy non-aluminum pot, melt butter, add all-purpose flour and cook on moderate heat for 2 minutes, stirring constantly with a wire whisk. Add the milk and bring just barely to the boiling point. Turn off the heat and add Fontina cheese and blend into the hot milk. Adjust the salt and pepper.
For the Pasta and Vegetables; add the butter or margarine and olive oil to a large, heavy skillet over medium heat and sauté the vegetables and ham together until crisp tender. Stir frequently.
Drain the pasta and blend with the vegetable-ham mixture; add the hot sauce and blend again, to coat all ingredients with sauce. Pass grated Parmesan at the table.Makes 4 Source: