Heat your wok or large skillet over high heat and add the cooking oil, swirling to coat the bottom evenly. The oil should shimmer but not smoke.
Add the minced garlic to the hot oil and stir constantly for about 30 seconds until fragrant, then immediately add the minced onions. Cook this mixture for 1-2 minutes, stirring frequently to prevent burning while letting the onions soften and become translucent.
Toss in the sliced ginger and continue sautéing for another minute until the ginger releases its aromatic oils and the kitchen smells incredible.
Add the diced pork to the wok and reduce heat to medium. Cook the pork for about 5 minutes, stirring occasionally, until the pieces are browned on all sides and starting to render their fat.
Stir in the bagoong and chopped chilies, mixing everything together for about a minute to let the flavors meld and the shrimp paste cook slightly.
Pour in 1 cup of the coconut milk and bring the mixture to a gentle boil, stirring to combine all ingredients into a cohesive sauce.
Add all the chopped spinach to the wok and stir everything together. Don't worry if it looks like too much spinach - it will wilt down dramatically.
Cover the wok and reduce heat to low, then simmer for 20 minutes, stirring occasionally to prevent sticking. The liquid should reduce significantly and the spinach should be completely wilted and tender.
Remove from heat and taste for seasoning, adding more bagoong if needed for saltiness or more chilies for heat.
Transfer to a serving dish and serve immediately with steamed white rice while hot.