Mash the tuna, drain the corn. Cut the feta, Gouda, the cucumber, paprika, onion and the garlic into fine cubes. Put everything in a large salad bowl and mix well. Mix the sour cream with the cream until it is creamy and add 1 tablespoon Maggi. Pour everything over the salad. Salt, strong pepper and add vinegar to taste. Mix well again. Let it steep for about 15 minutes. Serve with white bread and a glass of red wine.