Chop the rosemary and sweat it all together with olive oil in a pan. Add the tomatoes.
¼ sprig of rosemary, 1 tablespoon olive oil
Dice the apple and add it to the pot. Now add birch sugar, curry powder, wine vinegar, bay leaf, mustard seeds, paprika, nutmeg, ginger powder and chili powder if you like.
Let the sauce simmer very gently for 20 minutes. Stir again and again so that it does not burn.
Take the pot off the stove.
Season with salt and pepper, stir and puree very finely with a hand blender or smoothie maker. Mix the starch with 2 tablespoons of tap water and stir into the ketchup.