The message
from Martin contains these words:

Jenny said
I remember stuffed marrow that my mother used to make.......
It was yucky !! Watery marrow stuffed with mince :~(

My mother didn't used to make watery marrow, but whatever we do we
always end with watery marrow.

You may be cooking it too cool or covered. That water needs to
evaporate off.

Cut the marrow into shallow rings, 2cm deep,, scoop out the seeds,
pat off any juice with paper towel, and arrange them in a barely-oiled
shallow roasting tin. Brush rings lightly with olive oil. Stuff. Cook
uncovered at the top of a preheated very hot oven (the hot oven in an
Aga; 225. C until the marrow is tender and golden. There should be no
water at all swimming around in the tin.

Janet.