Pre-heat oven to 400°F. Rub the suprêmes with lemon juice, salt and pepper lightly.
Heat the butter in casserole until foaming. Roll the suprêmes in the butter, cover with the paper round, cover the casserole and place in pre-heated oven for 6 minutes.
After 6 minutes: press the top of suprêmes with finger. If still soft, return to oven for a moment or two.
When the suprêmes are springy to the touch they are done. If they are firm, they are over-done. They will still be good to eat - but don't compare to those in which the juice runs yellow.
Remove to warm platter and cover while making the sauce.