Peel the kohlrabi and carrots and roughly dice.
Wash and quarter the pepper, deseed and cut into pieces.
Peel and finely dice the onions and garlic.
Heat the oil in a frying pan and saute the onion and garlic over a medium heat for 3-4 minutes until translucent.
Add the remaining vegetables, except the tomatoes, to the pan and saute for 2 minutes.
Tip in the rice and half the paprika powder and cook, stirring, for about 1 minute.
Pour in the stock, stir well, bring to the boil and season with salt and pepper.
Put the rice pan in the preheated oven at 350°F (325°F fan, gas 4).
Meanwhile, mix the yogurt with 1 tsp lemon juice and the remaining paprika powder and season with salt and pepper.
Wash the spring onions and cut into fine rings. Scatter over the rice to garnish and serve with the paprika yogurt.