Mix the spices in a bowl. Sprinkle 4 teaspoons over the beef and press to adhere.

Heat the olive oil in a large pot over high heat. Add the beef (in batches if needed) and brown well on all sides. Transfer to a plate.

Reduce the heat to medium. If the pot looks dry, add a little more oil.

Add the garlic and onion and sauté for 3 minutes, until softened.

Add the orange juice and lime juice, scraping up the browned bits from the bottom of the pot.

Add the tomato puree, beef stock, water, and remaining spice mix. Stir, then return the beef to the pot.

Cover, bring to a boil, then reduce to a gentle simmer.

Cook for 2 hours, then remove the lid and simmer for another 30 minutes, until the beef is tender enough to shred.

Remove the beef from the sauce and shred with two forks.

Simmer the sauce uncovered for 10 to 15 minutes, until reduced and thickened to your liking. Season with salt to taste.

Return the beef to the sauce (reserve some sauce for drizzling over dishes like tacos or burritos, if you like).