Cook artichoke hearts according to package directions, substituting seasoned salt for salt.
Drain and set aside.
Meanwhile, heat butter in a double-boiler top; add mushrooms and onion and cook, stirring occasionally, until mushrooms are lightly browned.
Blend in a mixture of the flour, salt, pepper, and nutmeg.
Heat until bubbly.
Remove from heat and add broth and cream gradually, stirring constantly; bring sauce to boiling and cook 1 to 2 minutes, stirring constantly.
Remove from heat and vigorously stir about 3 tablespoons of the mixture into egg yolks.
Immediately return to double boiler.
Cook over boiling water 3 to 5 minutes, stirring slowly so mixture cooks evenly.
Mix in artichoke hearts, parsley, and capers.
Heat thoroughly.
Spoon mixture into warm patty shells.
Replace patty shell tops or garnish with a tiny fancy shape cut from a crimson cinnamon apple or a grenadine pear.