Fat and Flavor

• The notion of using oil as a sauce -- even a virtuous oil such as olive oil -- might seem odd if you're always trying to cut fat from your meals, but it's a technique with a strong pedigree. It's little different in any practical way from putting butter on a baked potato, or drizzling an oil-based vinaigrette over a salad. Both act as sauces, taking advantage of fat's ability to convey flavors to the palate more effectively and reliably than water-based liquids. A good olive oil adds its own flavors to the pasta, as well as those of the other aromatic ingredients.

Layering Your Flavors

• The first step in preparing spaghetti aglio e olio is infusing the oil with flavors. While the pot of water is coming to a boil for the spaghetti, peel several large cloves of garlic and slice them thinly. You can use just a clove or two for two portions, but it's better with a generous quantity. Heat a small pan or skillet over medium heat, and gently brown the garlic until just golden in the olive oil. Don't let it burn, which gives it a harsh and unpleasant flavor. Add a few pieces of dried chili to the oil, then remove the pan from the burner and wait for the spaghetti to finish cooking.

Oil and Water

• There's an adage that oil and water don't mix, but in this instance they do. Reserve about 1 cup of the cooking water when you drain the pasta, then return the pasta to its pot and pour in the garlicky oil. You don't need much, only about 2 tablespoons of the richly flavored oil for each portion of pasta. Toss the spaghetti until it's well coated, adding a few splashes of the cooking water. The starch in the water bonds the oil molecules loosely to the water molecules, making a simple emulsion that thickens the oil and helps it cling nicely to the pasta.

Other Ingredients

• The oil and chilies usually have a few other ingredients to keep them company. Some coarsely chopped Italian parsley is a nearly universal addition, lending the dish a welcome dash of color and bringing out the flavors of the toasted garlic. A sprinkling of good Parmesan or Asiago cheese makes the dish richer, or you can toss the pasta with toasted and seasoned breadcrumbs. It provides an appealing textural contrast, at a much lower cost than high-quality cheese.

Taking It Down a Notch

• If you're looking for simplicity -- and have a really good olive oil in your pantry -- you can make it even simpler. Just drizzle a small quantity of the oil over the pasta, and toss it with your favorite herbs or cheese. This keeps the focus squarely on the flavor and quality of your olive oil, a level of scrutiny that good oils can live up to in their own right.