- Coarse salt and freshly ground pepper
- 3/4 pound celery root, peeled and cut into 1/2-inch pieces (2 cups)
- 3/4 pound potatoes, peeled and cut into 1/2-inch pieces (2 cups)
- 3/4 pound carrots, peeled and cut into 1/2-inch pieces (2 cups)
- 1/4 cup extra-virgin olive oil, divided
- 1 onion, diced
- 2 small firm, sweet apples, peeled and cut into 1/2-inch pieces (2 1/2 cups)
- 1/4 cup roughly chopped fresh sage leaves
- Bring a medium pot of water to a boil, and generously season with salt. Add celery root, and simmer 3 minutes. Add potatoes and carrots, and simmer vegetables 2 minutes more. Drain well, and spread vegetables on a rimmed baking sheet. Let cool 15 minutes.
- Heat 2 tablespoons oil in a large (preferably cast-iron) skillet over medium-high heat, and cook onions until translucent and just beginning to color, about 2 minutes. Add remaining 2 tablespoons oil, the apples, and vegetables; season with salt and pepper. Stir to combine, then press into a single layer using a spatula. Cook, undisturbed, 2 minutes. Stir, and repeat process until vegetables are very tender and beginning to caramelize, 8 to 10 minutes more. Remove from heat. Stir in sage, and season with salt and pepper.