Part boil the potatoes. Cut the lamb into 5cm chunks. Cut the squash and courgette into large chunks. Quarter the tomatoes. Tip the lamb, potatoes, squash, courgette, tomatoes, garlic, artichokes, oil, salt and pepper into a large roasting tin and mix together with your hands until everything is glistening. Spread everything out in the tin. Bake for 45-55 minutes, splashing with wine halfway through the cooking and stirring everything gently.
Meanwhile make the pesto. Put the almonds into a food processor and whizz until chopped. Add the mint, mustard and lemon and whiz to a rough paste. Gradually add the oil and season well. Spoon the pesto into a small bowl and put on the table for everyone to drizzle over their lamb and vegetables.