Place the garlic, chilli, bread and mint in a food processor and pulse until finely chopped. Tip into a bowl and mix with the lamb, egg and seasoning. using damp hands, shape into 16 small meatballs.
Heat half the vegetable oil in a large non-stick frying pan. Fry the meatballs in batches over a high heat until golden, then set aside.
Heat the remaining oil in the frying pan, add the onion and cook for
3-4 mins until beginning to soften. Add the curry paste and fry for 1 min, then tip in the tomatoes and stock and bring to a simmer.
Add the meatballs and simmer for 15 mins until the sauce is thickened. Stir through the spinach until just wilted. Scatter over the reserved mint leaves, and serve with rice and cucumber & mint raita, if you like.