Heat oven to
325F (160C). Butter a shallow baking pan, about 12 x 7 x 2 inches (30.5
x 18 x 5 cm). Cut fish into serving-size pieces. Sprinkle both sides
with the salt and pepper and lay in prepared pan in a single layer.
Sprinkle with grapefruit juice. Mix bread cubes, butter and thyme and
sprinkle over fish. Bake 15 minutes. Lay sections of grapefruit on top
of fish. Brush them lightly with butter and continue baking 10 minutes
more or until fish flakes easily with a fork. Serve immediately.