Chile-Braised short ribs

 2 1/2 lb. (2"-thick) cross-cut bone-in short ribs (flanken style), cut into 2x2" pieces

Kosher salt

2

dried guajillo or ancho chiles, seeds removed

1

large onion, sliced into 1/2"-thick rounds

5

garlic cloves, unpeeled

1

tsp. crushed red pepper flakes

1

tsp. ground coriander

1

tsp. ground cumin

1

/2 tsp. ground cinnamon

3

Tbsp. vegetable oil, divided

2

Tbsp. tomato paste

1

acorn squash (about 1 lb.), peeled and seeds removed, sliced lengthwise into 1"-thick wedges

Plain whole-milk Greek yogurt, cilantro sprigs, and lime wedges (for serving)

Step 1

Season ribs with salt. Let sit at room temperature 1 hour, or chill, uncovered, up to 12 hours. If chilling, let sit at room temperature 1 hour before cooking.

Step 2

Meanwhile, place chiles and 5 cups hot water, or stock (for more flavor) in a blender and let sit while you prep onion and garlic.

Step 3

Heat broiler. Broil onion and garlic on a rimmed baking sheet, undisturbed, until charred on top (don’t worry if they get super dark), 8–10 minutes.

Step 4

Pop garlic out of their skins and place garlic, onion, red pepper flakes, coriander, cumin, and cinnamon in blender with chiles. Blend until smooth but still speckled with chiles; season purée lightly with salt. Set aside.

Step 5

Heat 2 Tbsp. oil in a medium heavy pot over medium-high. Working in 2 batches, cook ribs, turning occasionally and reducing heat if needed, until browned all over, 10–12 minutes per batch. Transfer to a plate.

Step 6

Carefully pour off oil and wipe out pot. Pour remaining 1 Tbsp. oil into pot and place back over medium-high heat. Add tomato paste and cook, stirring often, until tomato paste begins to separate and stick to pot, about 3 minutes. Stir in chile purée. Return ribs to pot and bring liquid to a simmer. Partially cover pot and cook, reducing heat to low to maintain a very gentle simmer, turning ribs occasionally, and skimming any excess fat from surface, until meat is very tender, 3–3 1/2 hours. (If sauce gets thick before meat is done, add water as needed to thin out a bit.)

Step 7

Add squash to pot and push down so it’s mostly submerged. Bring to a simmer and cook, uncovered, until squash is tender and liquid is thickened and saucy, 18–20 minutes.

Step 8

Serve ribs and squash, topped with yogurt and cilantro, with lime wedges.

Step 9

Do Ahead: Ribs (without toppings) can be made 3 days ahead. Cover and chill.