In a Dutch oven, heat a few tablespoons of oil over medium-high heat. Once hot, add the beef chuck pieces in batches, searing for 5-7 minutes until caramelized.

Lower the heat to medium and add the sliced onion, minced garlic, and ginger. Sauté for about 3 minutes until onions are soft and translucent.

Stir in the star anise pods and the bruised stalks of lemongrass, toasting for 1 minute to enhance their flavors.

Pour in the fish sauce, soy sauce, and brown sugar, stirring to combine well and dissolve the sugar.

Add enough water to cover the beef completely, bring to a boil, then reduce heat to low and cover, simmer for 1.5 to 2 hours.

Taste the broth and adjust the saltiness by adding more fish sauce or soy sauce if necessary.

Once the beef is fork-tender, ladle the stew into bowls and top with cilantro, green onions, and chili slices.