Place the onions in a medium-size skillet with the stock.
Cook the onions slowly over low heat until they are tender.
Add a few drops of water, if necessary, to prevent scorching.
Add the orange juice, wheat kernels, orange rind, and marjoram.
Stir until the wheat kernels are heated through.
Cover and keep warm while preparing the fish.
Place the pompano in a large skillet with enough boiling water to nearly cover.
Arrange the orange slices over the fish.
With the water barely simmering and the pan partially covered, poach the fish until opaque throughout, about 8 to 10 minutes.
Place the wheat pilaf on a serving plate.
Arrange the fish fillets over the pilaf and garnish with the scallions, if desired.