Finely chop the rosemary. Bring the vegetable stock to the boil along with the rosemary. Slowly stir in the polenta. Let the polenta soak on a low flame for 5 minutes. Then pull from the stove.
Quarter the zucchini lengthways and then cut into cubes approx. 2 cm wide. Fry the zucchini in the rapeseed oil until they are brown. Season the sour cream with the juice of the lemon.
Cut the salmon into 2 cm cubes and add to the zucchini. Add the sour cream and season everything with salt and pepper. Let simmer for another 3-4 minutes on a low flame, until the salmon is cooked through.
Then serve with the polenta and garnish with a little rosemary.