In a bowl, whisk together soy sauce, oyster sauce, cornstarch, and ½ cup water. Set aside.
Heat oil over medium heat and brown the ground meat, breaking it up and cooking until browned and crispy. Season with salt and pepper to taste. Once cooked, push the pork to one side of the wok.
Sauté garlic and onion until softened. Add the tomatoes and cook until they caramelize.PRO TIP: Allow the aromatics to break down and caramelize slowly, adding more oil as needed. This process creates a rich and flavorful base, so don't rush it.
Add the thin slices of bittermelon, mixing it well with the other ingredients. Sauté until tender but still crisp, about 3 minutes.
Make room in the center of the wok by pushing the ampalaya to the sides. Add a bit of oil, then pour the beaten eggs into the center. Let the eggs set for about a minute, then gently stir to scramble and mix them with the rest of the ingredients. Be careful not to overcook the eggs; they should remain tender and slightly moist.
Pour the prepared sauce over the mixture and stir everything together. Let it cook for a few minutes until the sauce thickens. Then, turn off the heat.
Notes
Ampalaya: To reduce the bitter taste, make sure to remove the white pith and seeds using a spoon. Then, massage a generous amount of salt into the slices and let them sit for about 15 minutes. Rinse and gently squeeze the slices afterward. You can also quickly blanch them in boiling water with a bit of baking soda for a minute, then rinsing them with cold water to stop the cooking process.
Ground pork: Feel free to use another protein like ground chicken or beef, shrimp, or tofu.