1. Preheat the oven to 200°C. Peel and finely chop the onions, ginger and garlic, then deseed and finely slice the capsicum. Heat 1 tablespoon of olive oil in a large frying pan over a high heat. Add the mince, garam masala, cinnamon stick and cardamon pods and fry for around 5 minutes, or until cooked through and lightly browned, stirring regularly.
2. Remove to a bowl and set aside, then place the pan back on the heat. Turn the heat down to medium and cook the onion, ginger and garlic for around 5 minutes, or until softened, then add the capsicum for a further 5 minutes. Tip in the tinned tomatoes, breaking them up with a spoon as you go, then pour in half a tin’s worth of water and stir well. Turn the heat up to high and bring to the boil, then reduce to a low heat, stir the mince back into the pan and simmer for 25 minutes, or until thickened, stirring occasionally.
3. Meanwhile, peel the potatoes, cutting any larger ones into quarters and place in a large saucepan. Cover with water, add a good pinch of salt and cook for 20 minutes, or until tender.
4. Drain in a colander and leave to steam dry, then return the potatoes to the empty pan. Add a knob of butter, a splash of milk, a good pinch of salt and pepper, then mash well. Stir the peas through the mince, season with salt and pepper, then remove the cinnamon stick and transfer to an ovenproof baking dish (roughly 20 x 25cm).
5. Evenly spoon the mash over the top, smooth the surface slightly, then use a fork to fluff it up – this will give you great texture once it’s cooked. Drizzle the pie with a little olive oil and season lightly. Cook in the oven for around 30 minutes, or until golden and bubbling.