I like an all-in-one dish that cooks by itself, with little or no skill!
First I peel and finely slice three large potatoes and arrange them in an oiled non-stick roasting dish. I then add a few tomatoes (halved cherry or date are good) and stoned black olives, season well and add a dribble of olive oil. I mix chopped herbs (marjory or thyme or parsley would do) with breadcrumbs. I brush three fillets of perch with oil and press them into the breadcrumbs. I place the fish on top of the potatoes, season, strew with what’s left of the breadcrumbs and add another dribble of oil. The dish cooks for 30 minutes at 200°C.
Perch is good value, but other thick fillets of white fish would work too.