Possible Clues:

• Topping made with pine nuts
• Sauce is nuisance on ring
• Pasta sauce mainly of basil and cheese
• Sauce with a name derived from the Italian for 'pounded'
• Sauce can give headache when served with duck
• Nuisance taking first portion of onion sauce
• Sauce traditionally prepared in a mortar
• Green sauce for rotini
• Sauce is something unwelcome on duck
• Pine nut sauce