Boil the pasta in plenty of water until cooked al dente (around 12-15 minutes).
Meanwhile, add the peeled garlic clove to a mini food processor, along with the Peppadews and fresh parsley. Blitz until roughly chopped.
Add the lemon juice, cream cheese, Greek yogurt, and a generous amount of salt and pepper. Blitz again to produce a fairly smooth sauce (a few lumps are okay!).
When the pasta is cooked, drain it, and add the sauce, the watercress, and the pine nuts. Mix well to combine. Place over a low heat for a minute or two, stirring constantly, to heat through, then serve.