Slice off a sliver on the bottom of each squash half so they can sit flat.
Place squash, cut side down in an oven proof dish pour in about 1/2 inch of water, cover with foil and steam in a 375f oven until tender, turn over after 30 minutes and test for tenderness (it will take approximately 45 min total or less depending on size of the squash).
Combine filling ingredient s and spoon in enough to have a rounded top on each squash.
Put back in the baking dish with the water, stuffed side up.
Cover loosely with foil and bake in 350F oven for apprx 30 minutes, uncover& bake a further 15 minutes.