Polenta with prawns

Start preparing the polenta. Put a litre and a half of water to heat in a pot. When the water is hot, add salt and sprinkle in the flour stirring with a whisk. It is very important, to pour in the flour before the water boils to prevent lumps from forming. Then cook for 40 minutes. Chop the parsley and the rosemary needles, cut the chilli pepper. Heat the vegetable stock and peel the cherry tomatoes and dice them. Clean the onion, slice it very finely and fry it gently in a saucepan with the oil; add the chopped anchovy fillets and mash them with a wooden spoon to melt them; add the garlic, the chopped parsley, rosemary needles and chilli pepper; allow the flavours to blend; pour a ladle of stock and add the diced cherry tomatoes. Cook the sauce for about 15 minutes. After the indicated time, put the prawns in the saucepan with the tomato sauce and continue cooking for another 5 minutes over a moderately high heat. Season with salt. Distribute the polenta in 4 heated soup plates, forming a sort of nest; arrange the prawns with their sauce in the centre and serve immediately.