Halve 1 of your pears. Scoop out the seeds from 1 of the halves. Peel it and pop the pear half in a food processor or blender with 100ml water (see our tip if you don’t have one). Crush 4 cardamom pods and shake in the black seeds. Finely grate in the lemon zest and squeeze in the juice from one half. Season and blitz to a purée.
Lay the chicken breasts between 2 pieces of cling film and bash with a rolling pin a few times to flatten them. Prick them all over with a fork. Pop the chicken breasts in a dish and spoon over half the pear purée. Rub it into the chicken. Keep the remaining purée for later.
Halve the fennel bulb and cut into 2cm thick wedges. Peel and core the remaining 2½ pears. Slice them into similar sized wedges. Set aside for a few mins.
Warm a large frying pan over a high heat for 2 mins. Add ½ tbsp oil. Put the chicken breasts in the pan. Fry for 2-3 mins on each side till browned and cooked through – the juices should run clear when you pierce them with a skewer. Transfer the chicken to a board, loosely cover with foil and leave to rest while you make the rest of the salad.
Put the frying pan back on the heat and add 1 tsp oil. Add the fennel and pear wedges. Fry for around 10 mins, turning a few times till nicely golden and a little charred around the edges. You may need to do this in 2 batches if your pan isn’t big enough.
Tip the charred veg into a large bowl. Add the watercress and the remaining pear purée. Toss together to mix.
Tip the walnuts into the frying pan. Toast for 2-3 mins till they’ve browned a little. Serve the chicken with the salad, scattered with the toasted walnuts.