Make-Ahead Vegetarian Chipotle Gravy

1 tablespoon vegetable oil or butter
1 large onion, peeled, coarsely chopped
1 large carrot, peeled, coarsely chopped
2 celery stalks, coarsely chopped
1 apple, peeled, coarsely chopped
A small handful of rosemary, thyme, and/or bay leaves
1 cup cider or dry white wine
6 cups (or more) vegetable stock (can also use chicken or turkey stock for non-vegetarian gravy)
3 tablespoons unsalted butter
1/4 cup all-purpose flour

2 teaspoons chipotle puree
Kosher salt, freshly ground pepper
 
Heat oil or butter in a large saucepan over medium-high. Cook onion, carrot, celery, and apple, stirring often, until everything in pan is deeply browned, 14–16 minutes. Add herbs and cook, stirring, until fragrant, about 1 minute. Pour in cider or wine and use a wooden spoon to scrape up any browned bits stuck to the bottom of pan. Bring to a boil and cook until liquid is reduced by half, about 5 minutes. Add stock and return to a boil. Reduce heat and simmer, stirring occasionally, until liquid is reduced by a third, 35–40 minutes.
 
Strain fortified stock through a fine-mesh sieve into a heatproof bowl. (You should have about 4 cups. If you don’t, add enough stock or water to get you there.) Discard solids. Keep fortified stock warm while you make your roux.
 
Heat 3 tablespoons unsalted butter in a medium saucepan over medium heat. Whisk in flour and cook, whisking constantly, until roux is golden brown and looks smooth and shiny, about 4 minutes.
 
Whisking constantly, ladle fortified stock into roux, pouring in gradually and making sure to incorporate each addition before adding more. Simmer, whisking often, until gravy is thickened and reduced to about 3 cups (it should coat a spoon), 8-10 minutes. Whisk in chipotle puree. Season with salt and pepper to taste.
 
Gravy can be made 5 days ahead. Let cool; cover and chill. Reheat over low before serving.
 
Serves 8.
 
From Bon Appetit, with changes