Pat bok choy dry. Add oil and ginger garlic paste to a wide skillet. Place over medium heat and cook, stirring occasionally, until the oil begins to bubble around the ginger garlic, but before it starts to brown.

Toss in the bok choy and spread into one layer, cut side down. Sprinkle with salt, then cook, without stirring, until starting to turn brown, about 2 minutes. Flip and cook for another 2 minutes or until the green leaves have wilted and the white bottoms begin to soften but still have some crunch.

Transfer to a platter and drizzle with chili oil if desired.