From Mastering the Art of French Cooking, Volume Two, by Julia Child and Simone Beck:
As described in the introduction to this seciton, jambon persille is a Burgundian creation. Inevitably when dealing with well-known regional specialties, there are dozens of variations and minor version, and always hundreds of very definite opinions on how to conduct teach step. Among the considerable number of serious and trustworthy formulas we have studied, this is the one we prefer.
A note on store-bought ham: If you are not using home-cured ham, buy 6.5 to 7 pounds of bone-in, ready-to-bake, mild-cured smoked ham or picnic shoulder. Omit step 1, proceeding directly to the simmering in Step 2; skin and bone the ham after cooking.
For 2.5 to 3 quarts of ham, serving 12 to 16.
1) Soaking the ham: 12 to 24 hours.
4 to 6 pounds of boned, home-salted fresh ham or shoulder-arm, and the salted ham rind
Soak the ham and the rind in a large basin of cold water, changing water 2 to 3 times. Overnight is enough for ham cured about 15 days, soak for 18 to 24 hours if ham has cured longer. (Soaking removes the preserving salt, not the flavor.)
2) Simmering the ham.
1 bottle best quality, young, strong, dry white wine (Cotes du Rhone or Pinot Blanc), OR 3 cups dry white French vermouth
3 cups bouillion made from ham bones or a mix of beef and chicken
Neccessary water
1 tsp thyme )
2 tbsp tarragon ) all tied in cheesecloth
4 allspice berries )
2 imported bay leaves )
2 large cloves garlic )
1 large onion, roughly chopped
1 medium carrot, roughly chopped
1 celery stalk
Place soaked ham and rind in kettle, add wine, boullon and enough water to cover by an inch. Add rest of ingredients listed, bring to a simmer and skim for several minutes until scum ceases to rise. Cover partially and maintain at the simmer until ham is tender when pierced with a sharp knife (about 2 hours for boned, home-cured ham). Let ham cool in liquid for an hour or two.
While still warm, remove rind from kettle (or ham, if still on a bone-in ham), scrape off and discard as much fat as possible and puree rind through coarse disk of food mill or fine blade of meat grinder; reserve in a 1 quart bowl. Tear ham apart with your fingers, discarding fat and gristle. Cut ham into pieces about 1/2 inch thick and 1.5-2 inches square, and place in a separate 2 quart bowl along with any meat scraps. Moisten with a tablespoon or so of cooking stock, and set aside. Thoroughly degrease cooking stock, boil down rapidly to concentrate flavor if necessary, and correct seasoning.
3) The aspic (about four cups)
5 cups thoroughly degreased ham-coooking stock in a saucepan
2 to 3 egg whites (1/2 cup)
1/2 to 1 cup minced green tops from leeks or scallions (optional)
2 packages (2 tblsp) powdered unflavored gelatin
Clarify the cookins stock with the egg whites, add optional greenery, strain, and then dissolve the gelatin in it.
4) The parsley and aspic flavoring
Bowl of pureed rind
1 cup chopped fresh parsley
1 clove garlic, mashed
1 tblsp dried tarragon or 3 tbsp fresh minced
1 tblsp wine vinegar
salt and pepper to taste
1 cup of the aspic, cool but not set
Mix all ingredients except the aspic in the bowl and just before assimbling the ham in Step 5, stir in the cup of aspic. (You will have 2 to 2.5 cups when all is blended.)
5) Assembling and serving
The following assembly method is informal: the meat is packed into a bowl and slices are cut and served directly from it. If you want a dressier presentation, line the bowl with aspic before filling it, and unmold onto a platter for serving.
Chill the bowl or crock you plan to use (2.5 to 3 qt) and spread a layer of parsley aspic in the bottom. Then pack with layers of ham and parsley-aspic. When filled, cover with a rack or plate that will fit into the bowl, top it with some kind of weight, and chill for an hour or so until set. (If you do not weight the ham, it will be difficult to cut into slice slater). Remove the rack and so forth, scumble the top a bit with a fork to disguise the plate or rack marks, and pour on some or all of the cool aspic (leftover from step 3). Cover and chill until serving time.