Roast the spices in 2 tablespoon oil together with the grated turmeric and ginger for a minute. Add 1 tbsp. oil and pour in onion, carrots, potatoes and garlic. Stir and cook without taking colour and add the red curry paste. Stir in the tomato paste and the vegetable stock. When it boil turn down the temperature and cover with a lid for 30 minutes.