Make the cashew milk: Combine the cashews with 2 cups of water and soak for 6 to 24 hours. Drain and rinse. Blend the soaked cashews with 3 cups of fresh cool water, the salt, sugar, and MSG (if using) until smooth, about 1 minute.

Braise the cabbage: Heat oven to 350°F. Reserve a small handful of sliced scallions for garnish.

Heat 2 tablespoons of the oil in a high-sided skillet with a lid or a Dutch oven over medium-high heat until shimmering. Add the cabbage wedges cut side down and sprinkle with ½ teaspoon kosher salt. Cook undisturbed until deeply browned, 6 to 7 minutes, occasionally pressing the wedges with a spatula (or another pan) to ensure good contact. Flip the wedges and repeat on the other cut side, seasoning with the remaining ½ teaspoon salt. Reduce the heat to medium-low and transfer the cabbage wedges to a plate.

Add the remaining 1 tablespoon of oil to the skillet along with the ginger, chiles, scallions, garlic, cinnamon, and coriander. Cook, stirring constantly, until aromatic and the scallions have wilted, about 1 minute.

Increase the heat to medium-high and add the sake, scraping up any brown and black bits that have developed on the bottom of the skillet. Cook until the sake is mostly reduced and the mixture holds a trail when you run a spatula along the bottom of the pan, about 5 minutes.

Add the cashew milk and bring to a bare simmer. Add the cabbage and cover the pan. Braise in the oven until the cabbage is tender and the cashew milk has thickened like pudding, about 45 minutes.

Meanwhile, make the fried shallots: In a small pot, combine the shallots and oil. Cook over medium-high heat, stirring constantly, until the shallots are lightly golden brown and crisp, 6 to 8 minutes. Remove from the heat and use a slotted spoon to transfer the shallots to a paper towel–lined plate.

Make the chile oil: Add the cashews to the oil and cook over medium heat, stirring constantly, until golden brown, about 3 minutes. Remove from the heat and stir in the gochugaru, salt, sugar, and MSG (if using).

Once the cabbage is tender, garnish with 2 tablespoons of chile oil, all the fried shallots, and the reserved scallion greens. Serve with steamed rice and additional chile oil alongside.