Season Flanken and sear on high heat until a crust develops on each side of the meat. Remove from the pot and set aside.
Roast the beets in aluminum foil in the oven, or boil them in water until tender.
To begin the stock, heat olive oil in a large pot and sauté leek, onion and carrots until softened (about 5 mins). Add in tomato paste, bay leaf, cooked beets and cover with water. Add in a bit of sugar for sweetness. Reduce the heat to low and let it simmer for 1-2 hours.
Place the meat back into the pot with another heaping tablespoon of tomato paste. Cook for another 30 minutes.
