Red Wine Braised Short Ribs

I made the of mistake thinking immersion blender-ing the veggies into the sauce would give it more body. Let's just say I'm not doing THAT again. 

Ingredients

1 large yellow onion

2 medium carrots

2 medium stalks celery

3 to 3 1/4 pounds bone-in beef short ribs

3 teaspoons kosher salt, divided

1/2 teaspoon freshly ground black pepper

1 tablespoon vegetable or canola oil

1 cup low-sodium beef broth (or reconstituted beef base)

2 bay leaves

4 fresh thyme sprigs (or some dried thyme)

1/4 cup all-purpose flour

2 tablespoons tomato paste

3 cups dry red wine

Instructions

1. Dice 1 large yellow onion, peel and cut 2 medium carrots into 1-inch pieces, and cut 2 celery stalks into 1-inch pieces.
    
2. Pat 3 to 3 1/4 pounds short ribs dry. Season all over with 2 teaspoons of the kosher salt and 1/2 teaspoon black pepper. Heat 1 tablespoon of the vegetable oil in a large, high-sided frying pan or Dutch oven over medium-high heat until shimmering. Add half of the short ribs and sear on 3 sides, 3 to 4 minutes per side.
    
3. Transfer to a 6-quart or larger slow cooker. If needed, add the remaining 1 tablespoon vegetable oil and repeat with the remaining short ribs. Transfer with tongs to the slow cooker. The short ribs will not be cooked through. Add 1 cup low-sodium beef broth, 4 fresh sprigs thyme, and 2 bay leaves to the slow cooker.
    
4. Add the onion, carrot, and celery, to the pot, season with the remaining 1 teaspoon kosher salt, and cook, stirring occasionally until softened, about 5 minutes. Add the all-purpose flour and tomato paste, stir to coat the vegetables and cook until darkened in color, about 2 minutes. Pour in 3 cups dry red wine and stir to combine, scraping up any browned bits. Bring to a boil. Reduce the heat and simmer until slightly thickened, about 5 minutes.
    
5. Pour the hot liquid and vegetables into the slow cooker. Cover and cook on the LOW setting for 8 to 10 hour or until meat is fork-tender and bone easily pulls away.
    
6. Transfer the short ribs to a large plate with tongs. Strain the liquid through a fine-mesh strainer into a large glass measuring cup or bowl and discard the cooked vegetables, bay leaves, thyme sprigs, and any loose bones. Serve the short ribs with sauce spooned over top.

Tip: If you have a fat separator, strain into that and pour leaving the fat behind. If you want to richen things up even more (which I barely recommend), transfer separated sauce to a pan and finish with 1 or 2 tbsp. COLD butter.

Serve over mashed potatoes or polenta.