Heat the oil in a large pot over medium-high heat. Sauté the onions for 3-4 minutes, then add the beef and garlic.Brown the meat, stirring regularly, for 5-10 minutes. All sides of the beef should be browned.

Add the carrots, celery, lentils, tomatoes, beef stock, wine, bay leaves, thyme, 1 teaspoon salt, and cayenne pepper. Bring to a boil, cover, then reduce heat and simmer for about 60-75 minutes, until the lentils and beef are tender. Stir in the tarragon. Then taste for salt and pepper. Serve.

NOTE: Use a pot with a heavy lid to keep in the heat. Otherwise you may have to cook the stew a bit longer for the meat to tenderize.