Put a large pot of water on to boil for the pasta. To start making the dressing, finely chop the parsley and mint and snip the chives. Put a mixture of all three herbs in a measuring jug; you will need about ¾ cup.
Grate the rind of the lemon and add to the jug with the wine vinegar or sherry vinegar and the extra virgin olive oil. Roughly chop the capers and black olives and add them to the jug, then season to taste with salt and black pepper. Mix well and put aside.
Check each scallop has had the small tough muscle removed, then rinse and dry on paper towels. Season with salt and pepper.
Add the tagliatelle to the saucepan of boiling water and cook for 5–7 minutes, or according to packet instructions.
Meanwhile, heat the olive oil in a large frying pan over high heat and gently fry the scallops for 2–3 minutes until lightly browned and only just cooked. Remove from the heat, pour on the dressing, and toss well.
Drain the pasta and serve on individual plates topped with the dressed scallops.