How to Make the Ultimate Umami-Bomb Vegetarian Demi-Glace
1 tablespoon unsalted butter
1 tablespoon extra-virgin olive oil
1 1/2 pounds green cabbage (half of a medium green cabbage), finely shredded
2 shallots, thinly sliced
Kosher salt and freshly ground pepper
In a large saucepan, melt the butter in the olive oil. Add the cabbage, shallots and a pinch of salt and cook over moderately high heat until wilted, about 5 minutes. Cover and cook over moderately low heat, stirring occasionally, until tender, about 10 minutes. Season with salt and pepper and serve.