Combine the oil and garlic in a small saucepan and bring to a boil.
Lower the heat and simmer 10-15 minutes, until lightly browned. Be careful not to burn the garlic or it will be bitter.
Remove the garlic from the oil and set aside (save the oil for vinaigrettes).
Combine the chicken stock, butter and cooked garlic in a medium saucepan and bring to a boil Lower the heat and cook at a full boil for 35-40 minutes, until slightly thickened.
Mash the garlic with a fork, whisk in 1/2 teaspoon salt and 1/4 teaspoon pepper and taste for seasonings.
Spoon the sauce over a meatloaf (1770s is sautéing 1 large Spanish onion in olive oil with 1-1/2 cup finely diced celery; the meat is 1 lb each of ground beef with ground veal with ground pork; parsley, thyme, chives; 3 beaten eggs with 2/3 cup whole milk and 2-1/2 cups panko).