
Bo Kho is a rich, fragrant Vietnamese beef stew with tender chunks of beef, carrots, lemongrass, and warming spices in a deeply savory broth. Served over noodles and topped with fresh herbs, it is hearty enough for dinner yet special enough for sharing with guests.
Place the beef in a large bowl and toss with the garlic, ginger, fish sauce, five-spice powder, and brown sugar until evenly coated. Cover and marinate for 30 minutes.
Heat the oil in a large Dutch oven or stockpot over high heat. Add 2 bruised lemongrass stalks and cook for 1 minute to perfume the oil, then stir in the remaining minced lemongrass.
Add the onion and cook for 2 to 3 minutes until softened. Add the marinated beef and sear, stirring occasionally, until browned on all sides, then mix in the tomato paste.
Cook the tomato paste with the beef for 5 minutes, stirring often, to deepen the flavor. Pour in the water and coconut water, then add the star anise, black pepper, chili powder, ground annatto, and paprika.
Bring the stew to a boil, then reduce the heat to low. Cover and simmer for 1 hour, stirring once or twice to prevent sticking.
Add the carrots, salt, soy sauce, and chili oil. Cover again and simmer for 40 minutes, or until the beef is tender and the carrots are cooked through.
Remove the bruised lemongrass stalks and star anise if desired. Cook the noodles according to the package directions, divide them among bowls, and ladle the hot stew over the top. Garnish with cilantro, Thai basil, and sliced raw onion, and serve with lime wedges.
For the best texture, use well-marbled beef chuck or brisket and simmer gently rather than boiling hard. If you cannot find coconut water, substitute more water or light beef broth. The stew tastes even better the next day and keeps well in the refrigerator for up to 3 days.