I have had my built-in double Zanussi oven for just over a month and cannot seem to brown food unless I grill it. I made potato wedges in top oven and although they were cooked through, they were still white; I overcooked baked squash in main oven because I was waiting for it to brown, but it didn't. What happens when I make lasagne, roast potatoes, cake? I spent a lot of money on this and am very unhappy. Any suggestions?