Pre-home freezer days, whenever there was a glut of fresh veg I would do a layered dish in a large casserole. Some of the veg I would gently pre-cook, such as carrots, parsnips, baby onions, swede etc.
I made a seasoned white sauce to which I added a tin of Campbells condensed mushroom soup (undiluted) and beat together. Poured this gently over the veg and the sauce would trickle through the layers.
Finished off with grated cheese added to a packet of crushed plain crisps and cooked in about gas mark 4 for an hour. Served with bacon or gammon.
Haven't cooked it this year but was looking for ideas for tomorrow, so there I have it.