Gradually whisk in oil, beginning with drops and increasing to a steady stream.

Gradually whisk in reserved milk and return to 4-cup measure.

Return to the heat and whisk for another minute and gradually add the stock.

Gradually whisk in the flour until there are no lumps.

Gradually whisk in about 1 cup of cooking liquid.

Cook over low heat a couple of minutes, then gradually whisk in the milk.

Remove from heat and gradually whisk in the chicken broth.

Gradually whisk in 1/4 cup of the hot cooking liquid.

Gradually whisk about 1/2 cup of orange mixture into the eggs to warm them.

Remove the pan from the heat and gradually whisk in the butter pieces.