Heat oil in a cooking pot or pressure cooker. Sauté garlic and onion.
Once the onion becomes soft, sauté the oxtail until light brown.
Pour water into the the pot. Let boil. Add beef cube. Stir. Cover and cook between low to medium heat until the oxtail becomes tender. This will take around 2 to 2½ hours for conventional cooking, and 30 to 40 minutes if a pressure cooker is used.
Once the oxtail is tender, add peanut butter and ground peanuts. Stir.
Pour in annatto water. Cook for 3 minutes.
Combine cornstarch and ½ cup cold water. Pour the mixture into the pot. Stir until the sauce gets thicker.
Add banana blossoms. Cook for 3 to 4 minutes.
Add eggplant and snake beans. Cook for 5 minutes.
Put the bok choy into the pot. Stir. Cover and cook for 2 minutes.
Transfer to a serving dish. Serve with hot rice and enjoy!