Drain the split peas and rinse them through with cold water. Set aside.
In a large saucepan, heat the oil and butter. Sauté the onion and garlic for a couple of minutes. Add the potato, carrots, split peas, spice and stock. Simmer rapidly for about 30 minutes, stirring occasionally.
Transfer to a blender and blitz until smooth. Taste and add any seasoning you want to – or extra spice. Feel free to loosen slightly with a bit of extra stock.
100g split yellow peas, soaked overnight (place in a bowl and cover with cold water)
2tbsp olive or rapeseed oil
A knob of unsalted butter
1 onion, diced
1 garlic clove, crushed
1tsp ground cumin or curry powder
1 large sweet potato, peeled and roughly chopped
2 large carrots, roughly chopped
1 litre hot vegetable stock