Place the walnuts in a dry skillet in a single layer. There’s no need to add oil or water.
Turn the heat to medium-low and toast the walnuts for about 3 to 5 minutes, or until fragrant and golden brown. Stir frequently and watch the walnuts closely. They can burn quickly once they get going.
Immediately transfer the hot walnuts to a plate to cool in a single layer. This stops them from cooking further and possibly scorching.
Microwave Method:
Spread walnuts on a microwave-safe plate, in a single layer.
Microwave on full power (100%) for 1 minute, stir, and then continue to microwave in 30 second intervals, stirring each time, until golden brown and fragrant. Watch them closely because they can burn quickly. The microwave may heat unevenly so stir the walnuts frequently.
Transfer the walnuts to another plate to cool, arranged in a single layer.
Oven Method (or toaster oven):
Preheat oven to 350ºF.
Spread walnuts in a single layer on a rimmed baking sheet, lined with parchment paper or foil for easy cleanup.
Bake 7 to 10 minutes, stirring every few minutes, or until golden brown. Watch the nuts closely; they burn easily. The walnuts near the edge of the pan brown more quickly than the ones in the middle of the pan, so it’s important to move them around.
Immediately spread the toasted walnuts on a plate in a single layer to cool. If you leave them in the hot pan, they may scorch because of the residual heat.
Video
Notes
Chopped walnuts will toast a bit more quickly than walnut halves.
Toast as many walnuts as you need. If you toast more than 1 cup at a time, the oven method works best.
Store both raw and toasted walnuts in either the refrigerator or freezer.
All 3 methods can be used to toast other types of nuts and seeds, too.