Heat the oven to Gas Mark 7, 220°C (425°F).
Put the mince, onion, egg, breadcrumbs, chilli, garam masala, half the ginger and half the coriander in a bowl. Season with a little salt and black pepper. Mix well, then shape into small balls – approximately 4cm in diameter. Put the meatballs, in a single layer, in an ovenproof casserole dish and drizzle over the olive oil. Toss gently. Place in the oven and cook until golden, about 15 minutes, until golden brown.
While the meatballs are cooking make the sauce. Heat a saucepan and add the curry paste and remaining ginger. Cook for a minutes, stirring all the time. Then add the tomatoes and continue to cook for 2-3 minutes. Add the coconut milk and bring to the boil. Reduce the heat and leave to simmer for 5 minutes.
Pour the sauce over the meatballs, mix well. Return them to the oven and cook for another 20 minutes. Just before serving stir in the lemon juice and scatter over the remaining coriander and the almonds. Serve with rice or steamed potatoes.