Begin by cutting the beef chuck roast into 1.5-inch cubes and patting them dry with paper towels.

In a Dutch oven, heat vegetable oil over medium-high heat until shimmering, about 2 minutes. Sear beef cubes in batches until browned.

Lower the heat to medium and sauté the diced yellow onion for 3-4 minutes until translucent, then add minced garlic and grated ginger for 1-2 minutes until aromatic.

Return the seared beef to the pot, stir in soy sauce, beef broth, brown sugar, rice vinegar, and red pepper flakes. Bring to a gentle simmer.

Cover and braise for 2-3 hours on low heat until fork-tender. Add broth if needed to maintain moisture.

Mix cornstarch with cold water to form a slurry, whisk into the pot to thicken the sauce. Simmer for an additional 5-10 minutes.

Serve beef bites over steamed rice or noodles, optionally topped with fresh herbs or sesame seeds.