Roasting pine nuts for pesto is a matter of personal preference. Some people prefer to roast pine nuts before using them in pesto as it can enhance their nutty flavor and aroma. Roasting the pine nuts can also help to remove any bitterness that may be present in raw pine nuts.
To roast pine nuts for pesto, you can simply spread them in a single layer on a baking sheet and bake them in the oven at 350°F (175°C) for 5-7 minutes, or until lightly browned and fragrant. Be careful not to over-roast the pine nuts as they can quickly go from golden brown to burnt.
However, if you prefer a milder, less intense flavor in your pesto, you can use raw pine nuts. Raw pine nuts can also be used to make pesto, and they will still provide a pleasant nutty flavor to the sauce.
Ultimately, whether to roast pine nuts for pesto or not depends on personal preference and the desired flavor profile of the finished dish.