Heat the vegetable oil in a large pot or Dutch oven over medium-high heat. Add the oil, minced garlic, onions, and sliced ginger. Sauté until fragrant and the garlic are golden brown.
Add the beef stew meat to the pot and brown on all sides.
Add oyster sauce, fish sauce, brown sugar, dark soy sauce, and stir to coat.
Add water or beef broth to the pot. Bring the mixture to a boil, then reduce the heat to low, cover, and simmer for about 1 to 1.5 hours or until the beef is tender.
Add the carrots and potatoes to the stew and continue to simmer until the vegetables are cooked through and the flavors meld together.
Season the stew with salt and pepper to taste.
Serve the beef stew hot, garnished with chopped green onions. You can serve it over steamed rice, noodles, and even mashed potatoes if desired.