Chicken with Tarragon Salsa Verde

The last time my mum was coming to visit, I was looking through Nigellissima for inspiration.  I mentally bookmarked the Chicken with Tarragon Salsa Verde recipe.  When mum arrived, I handed her the book and asked for suggestions for dinner.  Guess what took her fancy?  Nigella explains why she lists weight of herbs - it's more about the ratio here, 1 part tarragon to 4 parts parsley.  As it was just the 2 of us, I halved the quantities, and we both enjoyed some leftovers the next day.  Here I'll put the full amount though.  Serves 6-8.

Ingredients
For the chicken:
2 x 15 mL tablespoons olive oil
4 chicken breast fillets (preferably organic and corn-fed) with skin on (turns out it's impossible to find chicken with skin on around here)
small bunch fresh tarragon (2 sprigs for chicken plus more leaves for sauce)
pepper (preferably white coarsely ground), to taste (so, just regular old black pepper for me)

For the sauce:
leaves from small bunch fresh parsley (approx. 20g)
leaves from sprigs fresh tarragon (approx. 5g)
1 spring onion (including green part), roughly chopped
zest 1 unwaxed lemon and juice 1/2 lemon
1 teaspoon sea salt flakes or 1/2 teaspoon pouring salt, or to taste
6 x 15 mL tablespoons olive oil

Method
Preheat the oven to 220C.
Pour 1 tablespoon of the oil into a shallow ovenproof dish or roasting tin in which the chicken breast fillets will fit snugly and then arrange them in there skin-side up.  Tuck 2 sprigs of tarragon in between the chicken pieces, add a good grinding of pepper and dribble another tablespoon of oil over them, then pop them in the oven for 20-30 minutes, or until the skins are golden and flesh tender.
Take out of the oven, and let the cooked chicken stand for 5-10 minutes in the tin while you prepare the sauce.
Put the parsley and tarragon leaves, along with the spring onion, lemon zest, salt flakes and 3 tablespoons olive oil into a suitable receptacle and, using a stick blender, whizz to a paste, adding the lemon juice and remaining 3 tablespoons olive oil slowly as you blend.  Leave for a mo (seriously, that's what she wrote), while you slice the chicken.
Cut the chicken into thickish - 1cm or so - slices (if you need it to go further, then slice more thinly) and arrange on a platter.
Pour any juices that have collected in the tin into the tarragon salsa and whizz again with your stick blender, tasting for seasoning before dribbling the sauce over the tender sliced chicken.

This was really yummy, and really easy, and really good for a hot weather dish.  No standing over a hot stove, just chuck stuff in the oven, whizz stuff up in the blender, make it look as pretty as desired, and done.  It just might be my second-favourite method of cooking chicken (after poaching), and the sauce component is just begging for variations.