Angela Hartnett's barbecue chicken with watercress mayonnaise

I think the royal family are generally a good thing. The Queen gave me my MBE and I've met Prince Charles a couple of times at events and through working with Slow Food I was lucky enough to tour the gardens at Highgrove. Although I actually met him when I was younger and in the Brownies. We were on a trip to Canterbury Cathedral and he happened to be there, and being a good sport he did a little walkabout. And we've been fortunate enough to have a couple of the royals come to the restaurant, although I can't say who.

When you were younger you used to have pretty bad chicken dishes at parties, like the chicken drumsticks people always seemed to eat in the 70s. This is a more modern, updated take on party food, and still very British.

We're having a street party near where I live in east London. My sister's on the organising committee with the local vicar. I'm just helping out with the food, so I'll do as I'm told.

Serves 8
spatchcock chicken 4

For the marinade
thyme 2 tbsp, chopped
rosemary 2 tbsp, chopped
garlic 4 cloves, crushed
honey 4 tbsp
white wine vinegar 75ml
olive oil 50ml
tomato ketchup 2 tbsp
Dijon mustard 1 tsp
lime 1, rind and juice
sea salt and pepper to taste

For the mayonnaise
readymade mayonnaise 500g
watercress 1 bunch, finely chopped

Mix all the marinade ingredients in a bowl and season to taste. Cut the spatchcocks in half, season well and rub the marinade over the skin. On a barbecue, start to cook and crisp the chicken skin-side down, turn over and move further away from the direct heat until cooked – around 40 minutes.

Remove from the heat and rest. To finish, mix the watercress with the mayo and check seasoning. Serve with crisp green herb salad and watercress mayo.

Angela Hartnett is chef patron of Murano, London W1; muranolondon.com

Ashley Palmer-Watts' lamb chops, cooked over charcoal with broad beans and mint

This recipe is spring on a plate. British produce is incredible in the springtime, and each ingredient in this dish really makes the most of that by being cooked over charcoal. I use the barbecue at home as much as I do my frying pans – and here the delicious spring lamb and the cucumber are chargrilled.

I encourage people to use cucumber. Cooking with cucumber is something not many people would think of doing, but it's a very old thing. When we go through old recipe books for inspiration at the restaurant, it always crops up. The flavour of it hot – particularly barbecued – is something else, and the texture is firm but moist. You won't look back once you've tried it. With the cucumber juice and the chardonnay vinegar it creates a kind of cucumber ketchup that's very similar to one we have at Dinner. It's beautiful, and very elegant – perfect for a jubilee party.

The royal family are very connected to Dinner, actually, because when we're standing in the kitchen we can see the Royal Horse Guards go by each day. I have to pinch myself sometimes.

Serves 4

For the sauce
lamb stock 1 litre
lamb fat (reserved from making the stock) 1 tbsp
sprig of rosemary 1
sprig of mint 1

For the chops
spring lamb chops 8
clove of garlic 1
sea salt
freshly ground black pepper

For the garnish
cucumber 1 large
olive oil
shallot 3 tbsp, finely chopped
chardonnay vinegar 2½ tbsp
broad beans 250g, podded, blanched and peeled
dill 2 tbsp, chopped
flat leaf parsley 2 tbsp, chopped

To make the sauce, place the lamb stock into a saucepan and reduce to 100ml. Remove from the heat and whisk in the lamb fat and rosemary sprig. Set aside.

My preferred method of cooking the lamb chops would be over charcoal on a barbecue, but roasted in a pan over a high heat would also be great.

Cut the garlic clove in half and rub each of the chops with the garlic, then season with sea salt and coarsely ground black pepper – lightly press the seasoning on to the flesh so it sticks and drizzle over a little olive oil. Grill the lamb chops on a barbecue each side for 2–3 minutes until medium rare, and then wrap in foil to rest while cooking the garnish.

Juice a third of the cucumber and reserve the juice. Peel the remaining cucumber and cut in half, then cut the four sides off the cucumber to leave you with just the rectangular heart. Cut the cucumber sides into 5mm pieces and set aside.

Season the cucumber hearts and drizzle with olive oil, place on the barbecue and cook for 2 minutes per side until lightly coloured and soft. Set aside and keep warm.

Pour a thin layer of olive oil into a hot pan and add the cut cucumber pieces. Leave to colour, then gently turn to colour further. Reduce the heat and add the shallot and cook for 2 minutes. Deglaze the pan with the chardonnay vinegar and reduce until almost all gone.

Add 4 tbsp of the cucumber juice and peeled broad beans and heat gently to ensure the mixture remains moist, season with salt and pepper. Stir in the chopped herbs and serve.

Heat the sauce, add the remaining 2 tbsp of cucumber juice and add the sprig of mint.

Cut the cucumber hearts in half diagonally, place on the centre of large plate, spoon the broad bean and cucumber mix around and place the two chops on top of the garnish. Remove the mint from the sauce and pour a little of the sauce over the lamb chops.

Ashley Palmer-Watts is head chef at Dinner by Heston Blumenthal, London SW1; dinnerbyheston.com