Heat oil in a large skillet over medium heat. Sauté garlic, onion, and ginger until fragrant and slightly soft. The kitchen should smell rich and savory.
Add pork belly and cook until lightly browned on the edges. This builds flavor and adds depth to the sauce.
Pour in coconut milk and stir gently to combine. Bring to a gentle simmer, not a boil, to keep it creamy.
Add kalabasa cubes and cover the pan. Cook for 8–10 minutes until the squash is tender but still holds shape.
Add sitaw and cook for another 2–3 minutes. The beans should stay bright green and slightly crisp.
Add spinach and let it wilt for about 30 seconds. It should soften quickly into the sauce.
Stir in bagoong alamang for umami flavor and mix well. Let everything simmer for 1–2 minutes.
Season with fish sauce to taste and adjust salt if needed. The sauce should look creamy and coat the ingredients lightly.