(1) Cut broccoli into bite-size pieces. Discard the hard stem pieces, but : keep tender leaves and stem parts.
(2) Steam the cut broccoli for about 5-8 minutes, until just bright green : in color. Do not over- cook.
(3) In a 10-inch enameled (non-metal) skillet, heat 6 oz of butter until : melted. Add chopped garlic and wait until butter is hot enough to : cook in. Add steamed broccoli, then chervil to the skillet. Lightly : salt the broccoli.
(4) Cover, and cook over medium low heat, stirring occasionally with a : wooden spoon, for another 5-10 minutes or until the broccoli turns a : darker green color and becomes very soft.
(5) Mash the broccoli right in the skillet until no large pieces remain. : Use a potato masher or a strong wooden spoon. Mash until there are no : pieces remaining that are too big to fit in a soup spoon.
(6) While broccoli is cooking, add beaten egg yolk to 2 cups of milk.
(7) Put 3 Tbsp butter into a 2-3 quart saucepan. Use enamel or glass for : best soup flavor. Metal pans will make this soup bitter. Melt butter : and add flour. When the flour bubbles and starts to cook, add the : egg/milk mixture into the saucepan. Add the cardamom, mace, and white : pepper. Stir con- tents of saucepan constantly with wooden spoon : until thick. Lower the cooking heat.
(8) Empty the mashed broccoli mixture into the sau- cepan. Stir until : well-mixed. Slowly stir in the remaining milk and the cream. As soon : as the soup becomes hot enough to cook again, add the grated cheeses.
(9) Turn the heat down lower and simmer for about 5 more minutes, stirring : to allow the cheeses to melt and mix while the table is being set. : Serve immediately and retire quickly so as not to be trampled by those : who smelled it cooking.