Remove the bone, most of the fat and all of the gristle from the lamb and cut the meat into 1-inch cubes.
In a large Dutch oven, combine 2 tablespoons butter, the oil, onion, thyme, bay leaves, vinegar, stock and salt and pepper, to taste, and bring to a boil over medium-high heat. Add the lamb cubes and cook, covered, for 1 hour. The meat should be very tender, and there should be very little liquid left in the pan. If there is a lot of liquid in the pan, remove the meat and reduce the liquid over high heat, then return the meat to the pan.
In a small saucepan, melt the remaining butter and mix in the horseradish and parsley. Cook, stirring, over high heat for 1 minute, then pour the sauce over the meat and toss to coat. Serve immediately.
Brown Chicken Stock:
In a large, heavy-bottomed saucepan, heat the oil over high heat until smoking. Add all the chicken parts and brown all over, stirring to avoid burning. Remove the chicken and reserve. Add the carrots, onions, and celery to the pot and cook until soft and browned. Return the chicken to the pot and add 3 quarts of water, the tomato paste, peppercorns, and parsley. Stir with a wooden spoon to dislodge the browned chicken and vegetables bits from the bottom of the pan. Bring almost to a boil, then reduce heat and cook at a low simmer until reduced by half, about 2 hours, occasionally skimming excess fat. Remove from heat, strain, and press on the solids with the bottom of a ladle to extract out all liquids. Stir the stock to facilitate cooling and set aside. Refrigerate stock in small containers for up to a week or freeze for up to a month.
Yield: 1 1/2 quarts

Kitchen-Friendly View

Nutrition Facts

Per Serving Per 100 g

Amount Per 1 Serving
Calories	1572.13 Kcal (6582 kJ)
Calories from fat	1047.52 Kcal
		% Daily Value*
Total Fat	116.39g	179%
Cholesterol	572.29mg	191%
Sodium	1888.92mg	79%
Potassium	1206.1mg	26%
Total Carbs	19.41g	6%
Sugars	11.1g	44%
Dietary Fiber	5.2g	21%
Protein	106.47g	213%
Vitamin C	10mg	17%
Vitamin A	0.4mg	12%
Iron	8.5mg	47%
Calcium	160.2mg	16%

Amount Per 100 g
Calories	215.39 Kcal (902 kJ)
Calories from fat	143.51 Kcal
		% Daily Value*
Total Fat	15.95g	179%
Cholesterol	78.41mg	191%
Sodium	258.79mg	79%
Potassium	165.24mg	26%
Total Carbs	2.66g	6%
Sugars	1.52g	44%
Dietary Fiber	0.71g	21%
Protein	14.59g	213%
Vitamin C	1.4mg	17%
Iron	1.2mg	47%
Calcium	22mg	16%

* Percent Daily Values are based on a 2000 calorie diet. Your daily values may be higher or lower depending on your calorie needs.
Find out how many calories should you eat.