Mix the corn grits and the vegetable stock in a saucepan with a whisk, then bring to the boil. Stir regularly until a thick paste has formed. Put this in a bowl and set aside to cool.
Cut the bell pepper and zucchini into small pieces, finely chop the shallots and garlic.
Heat some olive oil in a saucepan and sauté shallots and garlic in it until translucent. Then add the vegetables and cook covered over medium heat for about 20 minutes, stirring regularly. Add the tomato pieces and season with salt, pepper and paprika paste.
Heat some olive oil in a pan. Turn the polenta out of the bowl onto a plate and cut into slices. Fry these in the pan until golden brown.