What "makes" this exceedingly simple recipe is the baked garlic that's stirred into the cheese sauce. Baking the garlic not only makes it soft, even creamy, it mellows the garlic scent and taste, making it milder and sweeter. It goes without saying that better ingredients make better food, and in this case that means good cheese, freshly grated. That said, I've found using canned evaporated milk rather than cream works fine, and you can get by with onions instead of shallots, though the shallots do make a difference. The original recipe is from Bon Appetit, October 2003 who attributes the recipe to The Federalist in the XV Beacon Hotel in Boston. It makes a very large quantity, so make sure you have a suitable container to mix the sauce and the cooked pasta. It freezes quite well; I like using ziplock bags which can be filled, flattened and frozen.
1 head of garlic
1 1/2 tablespoons olive oil
2 large shallots, minced
2 cups whole milk
2 cups whipping cream
1/2 teaspoon chopped fresh thyme
1/8 teaspoon finely grated lemon peel
8 ounces extra-sharp cheddar cheese, shredded
1/2 cup grated Parmesan cheese
1 pound ditalini or conchiglie or other "small" pasta
8 ounces quality ham, cut into 1/4-inch pieces (about 2 cups)
1 tablespoon chopped fresh parsley
Preheat oven to 350F. Cut top 1/4 inch off head of garlic to expose cloves. Place garlic, cut side up, on sheet of foil. Drizzle with 1/2 tablespoon oil; sprinkle with salt and pepper. Wrap garlic with foil to enclose tightly. Bake until skin is golden brown and cloves are tender, about 55 minutes. Cool (I tend to put them in the fridge). Squeeze cloves from their skin.
Heat remaining 1 tablespoon oil in large saucepan over medium heat. Add shallots; sauté until tender, about 4 minutes. Whisk in milk, cream, thyme, lemon peel, and roasted garlic. Simmer over medium heat until reduced to 2 3/4 cups, about 30 minutes. You don't want the milk/cream to boil or overcook. Reduce heat to low. Gradually stir in cheeses.
Meanwhile, cook pasta in large pot of boiling salted water until tender but still firm to bite, stirring occasionally. Drain.
Toss cheese sauce, pasta, ham, and parsley in large bowl. Season to taste with salt and pepper.