Heat the vegetable oil in a large wok or deep skillet over medium-high heat. Add the minced garlic, ginger, and chopped chili peppers. Stir-fry for about 1 minute until fragrant.
Add the crab pieces to the wok and stir-fry for 3-4 minutes until they turn bright red.
In a bowl, mix together the ketchup, sweet chili sauce, soy sauce, oyster sauce, rice vinegar, and sugar. Pour this mixture over the crab in the wok.
Add the chicken broth and bring the mixture to a boil. Reduce the heat to low, cover, and simmer for 15-20 minutes, allowing the crab to absorb the flavors.
Once cooked, remove the lid and increase the heat to medium-high to thicken the sauce for about 5 minutes, stirring occasionally.
Serve the crab hot, garnished with chopped green onions and fresh cilantro. Pair with steamed rice to soak up the delicious sauce.