Clean, peel, wash and drain the parsnips, carrots and beetroot. Cut vegetables into small cubes. Clean the cauliflower, removing the outer leaf veins. Leave the stalk to stand. Cut the cauliflower into slices about 1 cm thick. Mix 4 tbsp. oil, cumin, curry and 2 tbsp. agave syrup, season with salt and pepper. Marinate the cauliflower in the mixture for about 20 minutes. Fry in 2-3 portions in a large pan for about 3 minutes while turning. Take out, spread on a baking tray and bake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: see manufacturer) for approx. 10 minutes.
In the meantime, put the couscous in a bowl. Bring the broth to the boil, pour in and let it stand for about 5 minutes. Heat 4 tablespoons of oil in a large pan and fry the vegetable cubes in it with 1 teaspoon of agave syrup for about 8 minutes at medium heat. Loosen the couscous with a fork. Wash parsley, shake dry and chop finely, except for a few leaves for garnishing. Stir half of the chopped parsley into the couscous, add the rest to the vegetables, season with salt and pepper.
Remove cauliflower from the oven and arrange on plates with vegetable tartar. Garnish with the remaining parsley. Add couscous.