If using mussels: wash them and place them in a large saucepan over medium to high heat with a splash of white wine or water (you may need to do this in batches). Cover the saucepan and wait 1 or 2 minutes, until most of them are opened. Discard the ones that aren't, remove the meat from the shells and clean them, inspecting carefully inside each mussel.
If using calamari: clean it and chop it in 2 cm squares. Reserve in the fridge.
Peel and cut the potatoes in 1.5 cm dice. Place them in a bowl with cold water to prevent them from browning.
Chop the onion. Blend the garlic, chillies, turmeric and cumin with a bit of water to form a paste. Heat the oil in a pot or big saucepan and cook the onion and chilli paste for about 15 minutes over low heat.
Drain the potatoes and add them to the pot, along with the stock or water.
Cook for 10 - 15 minutes, until the potatoes are completely cooked through. Add the seafood and cook for one or two minutes, season with salt and pepper, turn off heat and add chopped mint. Serve with white rice and the veggies of your choice.
