Cut eggplant into strips (about 3 1/2 inches x 1/2 inch).
Heat canola oil in a wok over high heat. Add minced garlic and onions (sliced lengthwise) and stir-fry 30 seconds. Add eggplant slices and let sit 4 minutes or so, turning after 2 minutes, until blistered and brown in spots.
Add coconut milk, chili paste, fish sauce to taste and palm sugar (or brown sugar if you don’t have palm). Cover and braise over medium heat until eggplant is tender. Return to high heat, add scallions cut into 1-inch pieces, stir-fry 30 seconds, and serve hot.