Toast the pine nuts in a frying pan over a medium heat until they turn golden brown in colour (about 5 mins).

Grate the Parmesan cheese.

Peel & chop or crush the garlic clove.

Wash the watercress and tear the leaves from the stems.

Add the watercress, garlic, pine nuts, Parmesan cheese and plenty of salt and pepper to the food processor.

Turn on the food processor and drizzle the olive oil through the hole in the top until the pesto is the right consistency.

Serve over pasta, or with meat/fish/salad etc.