Basic Brown Sauce

2 ounces of  boiled ham, diced (optional)
1/4 cup of  carrots, finely chopped
1/4 cup of  onions, finely chopped
1/4 cup of  celery, finely chopped
4 tablespoons of clarified butter* or cooking oil
3 tablespoons of  flour
4 cups of  hot brown stock or enriched canned broth
1 tablespoon of tomato paste
1/4 teaspoon of dried thyme
1/2 bay leaf
2 parsley sprigs
Salt and pepper

Tie dried thyme, bay leaf and parsley sprigs in a cheesecloth. In a saucepan, sauté ham and vegetables in butter or oil until onion is soft and light brown, approximately 10 minutes. Blend in the flour and stir over low heat for another 10 minutes, or until the flour turns a golden nut brown.
Remove from heat, and quickly blend in all the hot stock. Add the tomato paste and herb-filled cheesecloth. Simmer over low heat for 1 1/2 to 2 hours, until sauce coats a spoon lightly. Skim off fat as necessary, and add more liquid if sauce thickens too quickly. Strain out the vegetables and adjust seasoning.
*Clarified butter is made by slowly melting unsalted butter so that the milk solids sink to the bottom of the pan and the clear liquid rests on the top. Any foam floating on top is skimmed off, and the remaining clear butter is poured or skimmed off the top of the milk solids. This clear, golden liquid is clarified butter.
VARIATIONS:
BROWN MUSTARD:
Sauté 1/4 cup onions in butter or oil until soft, about 10 minutes. Add 1 cup dry white wine and reduce to 3 or 4 tablespoons. Add 2 cups brown sauce and simmer 10 minutes. Remove from heat and add 2 to 3 tablespoons Dijon mustard. Serve with pork or beef.
MADEIRA OR PORT:
Reduce 1/2 cup Madeira or Port wine over high heat to 3 or 4 tablespoons. Add 2 cups brown sauce and simmer briefly. To finish, beat in a tablespoon or two of butter.

CURRY:
Gently sauté 1/2 cup finely minced onions in 2 tablespoons butter until soft (7 to 10 minutes), stir in 1 to 2 tablespoons curry powder, according to taste, and cook 2 minutes. Add 2 cups brown sauce and reduce at a simmer to 1 1/2 cups, stirring occasionally.
MUSHROOM:
In a large saucepan, sauté 1 cup sliced or minced fresh mushrooms in hot butter or oil until browned, about 5 minutes. Swirl in 1 tablespoon butter and add to 2 cups simmering brown sauce. As an extra embellishment, add 1/2 cup white wine to the browned mushrooms and reduce to a scant tablespoon before incorporating into the sauce. Delicious with fish, chicken, or veal.
TARRAGON AND WHITE WINE:
Reduce 1 cup of dry white wine and 4 tablespoons fresh minced tarragon over high heat to 2 to 3 tablespoons. Strain into brown sauce, and beat in extra parsley and/or tarragon and a little butter before serving.