Make the cornstarch slurry: in a medium bowl, whisk together the cornstarch and water. Set aside.
Heat the oil in a Dutch oven or other high-sided pan over medium heat.
Add the onions and garlic and sauté for 1-2 minutes, until soft and fragrant.
Add the chicken and cook about 4-5 minutes on each side, lightly browning on all sides.
Add the chicken broth, fish sauce, and annatto paste. Stir. Increase heat to medium-high and bring to a boil.
Once boiling, lower the heat to low-medium and cover and simmer for 25-30 minutes, just until the chicken is tender and around 155-160°F.
Uncover and stir in the peanut butter until well combined.
Add the cornstarch slurry and stir to combine.
Add the green beans and gently push them so they are mostly under the liquid.
Return the cover and cook, covered, for 5 minutes.
Uncover, add the bok choy, and cook for 2 more minutes, just until the bok choy has slightly softened.
Serve with a side of bagoong* or shrimp paste.
Notes
Makes approximately 6 servings. *Bagoong is a traditional Filipino paste made from fermented fish or shrimp that was temporarily banned in the US. Although no longer fully banned, it is actually challenging to find in the US. So if you are in the United States, you can use any jar of shrimp paste that you might find at your local Asian supermarket instead. You can substitute kale or spinach for the bok choy. Traditional Filipino kare kare is made with oxtail, eggplant, and long string beans. So this recipe is my Filipino-American version that is absolutely delicious!
Instead of oxtail, we use chicken, which is common enough and easy to find in any grocery store in the US.
This recipe leaves the eggplant out. Feel free to add it to the recipe if you wish.
Long string beans can be tricky to find sometimes depending on where you live, even in local Asian supermarkets, so this recipe uses regular green beans. They are just as delicious!