Whether you plan to sprinkle almonds over a salad or fold walnuts into a batter, toasting nuts will intensify their flavor and give them a crisp texture and attractive golden color. Large amounts of nuts are best toasted in the oven. Spread them in a single layer on a baking sheet and bake them in a 325°F oven, stirring occasionally to prevent overbrowning at the edges of the pan, until the nuts are golden, fragrant and coated in a thin layer of their own oil. Depending on the type of nut and the size of the pieces, this may take 10 to 20 minutes.
Toasting nuts in a microwave oven is quick and convenient. Although they will not turn golden, they will have much the same flavor as traditionally toasted nuts. Microwave them on a plate for 3 to 4 minutes, stirring them once about halfway through if the oven does not have a turntable. You can also toast small amounts of nuts in a dry fry pan on the stovetop. Cook the nuts over medium heat, stirring frequently, until they are golden. Keep a close eye on the nuts, especially pine nuts and sliced almonds, for they burn quickly.
Immediately transfer the nuts to a plate or paper towel and let them cool completely before using. Nuts will continue to toast, so cook them just a shade lighter than desired. They will become darker and crispier as they cool. Nuts easily develop acrid flavor if overbrowned, so just the exterior should be toasted, and the interior should remain lighter colored.
If needed, toast nuts in advance and store them in an airtight container at room temperature for up to 1 week.
Adapted from Williams-Sonoma Kitchen Companion: The A to Z Guide to Everyday Cooking, Equipment and Ingredients (Time-Life Books, 2000)