Arroz blanco con champinones

Assemble these supplies:

• 1 cup of uncooked rice 
• 2 quarts (8 cups) water
• 3 teaspoons salt 
• few drops lemon juice or vinegar (optional) 
• 1 pound fresh mushrooms 
• 1/8 cup butter
• 1/8 cup olive oil salt 
• 1/4 cup flour 
• 2 1/2 cups milk
• 2 egg yolks

Steps in preparation:

1. Prepare the rice according to the preceding directions for "White Rice." Keep hot in a colander or sieve.
2. Clean the mushrooms and slice them in several slices. Saute the mushrooms in the butter and oil with a few drops of lemon juice and salt. Cover and cook for 10 minutes, stirring occasionally. Blend in the flour. Remove from heat.
3. Stir in the milk gradually. Add more salt if necessary. Cook over low heat until the mixture is smooth, about 10 minutes. Beat the egg yolks in a cup and add them to the sauce. Heat again, but do not boil.
4. Arrange the rice around the edge of a serving dish. Put the mushroom sauce in the center and serve immediately.
5. SERVES 6.