Preheat the oven to 190°C/375°F, Gas Mark 5.
Place the chops on a rack in the roasting tin, so the excess fat runs out.
Cook for 20 minutes while you make the stuffing.
For the stuffing, grate sufficient zest from the oranges to give 1 tablespoon.
Halve the fruit and scoop out the orange segments, leaving the pith and skin behind.
Do this over a basin so no juice is wasted.
Melt the butter or margarine and mix with the orange zest, segments, breadcrumbs and herbs.
Moisten with the orange juice and season lightly.
Remove the chops from the oven, top the lean meat with the stuffing, then return to the oven for a further 15 to 20 minutes.
Serve garnished with watercress.