Add the remaining oil, onion, and peppers to the skillet. Cook for 4 minutes, until the vegetables begin to soften.
Add the tomatoes, garlic, ginger, cumin, coriander, turmeric, and cardamom. Cook for 3 minutes, stirring often.
Return the beef to the skillet, add the stock, and simmer for 4 to 5 minutes, until the sauce is glossy and the beef is tender.
Serve over rice with lime wedges.