from Curry Trail and adapted from The Kitchn
Choose firm, fresh herbs.
If you wish, you can chop them fine. Or leave them in larger sprigs and leaves.
Pack the wells of ice cube trays about 2/3 full of herbs. You can mix up the herbs, too, this can be used in recipes that calls for mixed herbs.
Pour extra-virgin olive oil or melted, unsalted butter over the herbs.
Cover lightly with plastic wrap and freeze overnight.
Remove the frozen cubes and store in freezer containers or small bags. Don’t forget to label each container or bag with the type of herb (and oil) inside!