1. Place the quail eggs in a small saucepan. Add enough cold water to cover the eggs by about 3cm. Bring the water to a boil, then simmer over medium-low heat for about 5 mins. Drain hot water and fill saucepan with ice cold water. Cool the eggs for 3 to 4 minutes. Peel and refrigerate until ready to use.
2. In a frying-pan, heat 1 tbsp vegetable oil and fry the garlic and the ginger until fragrant. Then add onion and spinach, fry until wilted. Add the ingredient "A" to season. Let it cool to room temperature.
3. In a bowl, add the vegetable mixture from #2 and ground beef. Combine well using your hands thoroughly until the mixture forms sticky and moist.
4. Take a small portion of the mixture (about 40g), and shape it into a flat, round disc shape, and then put an egg on it. Cover the egg with the meat mixture and make it into a round ball. Repeat until all of the meat mixture is used.
5. Preheat the oven at 200˚C and place them on a baking pan lined with baking sheet. Bake for about 25 mins.
6. In a saucepan, add all the sauce ingredient and bring it to boil. Place meatballs and simmer for about 10 mins or until the sauce is thick.