The thing with quorn is not to over cook it. You can actually eat it raw (I do with the chicken pieces, defrosted obviously) so you're not actually "cooking" it but reheating it. If you over cook it then it goes very dry (like my sausages for dinner last night) and then isn't very nice at all!
My fave's are the mince (gorgeous in a stew with potatoes, carrots, onions, veg oxos and marmite), pieces in a curry or fajita, the brown quorn burgers are fab on a wholemeal bap with cheese slice and a dollop of relish, sausages are great in a casserole/hotpot. The fillets in batter are reeeeeally nice with new potatoes and veg. The chicken and ham style slices are great for salads and sandwiches and the peppered grillsteaks are lovely with SW chips.