A simple but flavorful no-cook sauce close in style to traditional pesto.

For hundreds of years, pesto was made by pounding the ingredients in a mortar and pestle.

A scallions white bulb will be slimmer than a green onion’s.

Scallion pesto in white bowl with white spoon

Alison Bickel  / Simply Recipes

Spring onions are older than scallions and green onions.

They are slightly stronger in flavor and can be identified by their rounded white bulb.

However, after a while (likeguacamole), oxidation can cause your pesto to turn brown.

Scallion pesto in white bowl with white spoon

Alison Bickel  / Simply Recipes

The boiling water kills the browning enzymes that quickly cause the leavesand the resulting pestoto turn dark.

Once youre ready to use it, just stir in the oil to bring your pesto back to life.

The pesto will keep in the freezer for up to 12 months.

Scallion pesto in ice cube tray

Alison Bickel  / Simply Recipes

Set a bowl of ice water next to the stove.

Swish them around for 30 seconds.

Drain into a colander, and with your hands, squeeze out as much liquid as possible.

Scallion pesto in ice cube tray

Alison Bickel  / Simply Recipes

Pulse until finely chopped.

Scrape down the sides of the food processor with a rubber spatula.

While the food processor is running, slowly add the olive oil in a steady slow stream.

Blanching basil and parsley for scallion pesto

Alison Bickel  / Simply Recipes

Occasionally, stop to scrape down the sides of the food processor.

Taste and adjust the salt, pepper, and lemon juice as needed.

Blanched herbs in ice bath for scallion pesto

Alison Bickel  / Simply Recipes

Herbs being drained in colander for scallion pesto

Alison Bickel  / Simply Recipes

Making scallion pesto in food processor

Alison Bickel  / Simply Recipes

Making scallion pesto in food processor

Alison Bickel  / Simply Recipes

Pouring olive oil into food processor to make scallion pesto

Alison Bickel  / Simply Recipes

Scallion pesto in food processor

Alison Bickel  / Simply Recipes