2 tablespoons olive oil

2 pounds beef shank

salt and ground black pepper to taste

1 onion, cut into 1/2-inch cubes

2 stalks celery, cut into 1/2-inch cubes

1 cup Marsala wine

1 (14 ounce) can beef broth

water to cover

2 tablespoons dried tarragon

Preheat oven to 300 degrees F (150 degrees C).

Heat an oven-proof deep skillet with a lid over medium-high heat on the stove; add olive oil. Season beef shank with salt and pepper. Cook beef shank in the hot oil until browned on all sides, 5 to 10 minutes. Transfer beef shank to a plate.

Saute onion and celery in the same skillet until onion starts to get translucent, 5 to 10 minutes. Pour wine over onion mixture and bring to a boil while scraping the browned bits of food off of the bottom of the pan with a wooden spoon.

Return beef shank to onion-wine mixture; add beef broth and pour in enough water to cover 1/2 to 3/4 the beef shank. Sprinkle tarragon over shank; cover skillet with lid.

Bake in the preheated oven until meat is falling off the bone, at least 5 hours. Season with salt and pepper before serving.