For this recipe, I prefer medium Chinese eggplants, the pale purple, slender ones that are ten to twelve inches long, over similar-looking but more bitter varieties. This calls for oil blanching and, because eggplant is basically a sponge, brining them for an hour first until they are saturated but not bloated. During frying, the water turns to steam and makes the eggplant creamy and not at all oily.
Trim and discard eggplant ends. Cut eggplant into 1-inch (25 mm) thick wedges, by first cutting crosswise into equal-length chunks, approximately 3-inch (8 cm) long. Then cut each chunk in half lengthwise, repeatedly, to achieve 1-inch thick wedges.
In a large bowl, combine 1 quart (950ml) water and salt. Whisk until salt is dissolved. Submerge eggplant in brine and let sit at room temperature for 1 hour. About 20 minutes before brining is finished, fill a 5-quart or larger Dutch oven with oil and secure a deep-fry thermometer on the side. Set over medium-high heat and warm oil to 375°F (191°C). While the oil is heating, in a small bowl, combine remaining 1/4 cup water, oyster sauce, fish sauce, and sugar. Stir until sugar is dissolved.
Drain eggplant and place on paper towels to thoroughly dry. Take care to remove all excess water. You don't want any water clinging to the eggplant when you add it to the hot oil. Trust us on this one.
Add sliced garlic to hot oil and fry until crisp and light golden brown, about 30 seconds. Use a spider to remove them, place on paper towel to drain.
When the oil temperature returns to 375°F (191°C), carefully slide the eggplant into the oil. Stir until eggplant has darkened and caramelized at the edges, 3 to 4 minutes.
While the eggplant is frying, place a dry wok or large skillet over high heat.
Use a spider to lift the eggplant from the Dutch oven, letting excess oil drain back into the Dutch oven. Place eggplant in the screaming hot wok. Immediately add chopped garlic and most of the chile rings (reserve a few for garnish), toss to combine. Pour in sauce and continue to toss until the sauce thickens to a glaze and eggplants are browned at the edges, 2 to 3 minutes. Add most of the basil leaves and toss until wilted, about 20 seconds more.
Arrange contents of the wok on a serving platter. Crumble fried garlic and scatter over the eggplant with the rest of the basil and chile rings. Serve immediately.