Peel and finely chop the onion. Trim and peel the carrots. Finely chop them. Warm a pan over a medium heat for 1 min, then add ½ tbsp oil and the chopped veg. Season with a pinch of salt and pepper. Pop on the lid. Sweat for 10 mins, stirring a few times, till the veg start to soften. If they start to colour, turn the heat down.
While the veg sweat, peel and crush or grate the garlic. Peel and grate the ginger. Peel and grate the turmeric (you may want to do this onto a plate as it can stain). Stir them all into the veg with 1 tsp curry powder.
Pour in the coconut milk. Top up the pan with 600ml boiling water. Cover, turn up the heat and bring to the boil. Simmer for 15 mins till the veg are soft.
Ladle the soup into a blender and blitz till smooth, or use a hand-held blender in the pan. Taste and add a pinch more salt and pepper if you think it needs it. Serve in warm bowls.