The Best Slow Cooker Short Ribs With A Delectable Red Wine Sauce

Ingredients

• 4 lbs short ribs cut into 2- to 4-inch pieces
• 1 ½ tsp each kosher salt and coarsely ground black pepper, divided
• 1 Tbsp canola oil
• 2 carrots, cut in thirds
• 2 onions, quartered
• 1 head garlic, halved crosswise
• 2 Tbsp tomato paste
• 3 cups full-bodied red wine (like Cabernet Sauvignon)
• 2 sprigs rosemary
• 6 sprigs thyme
• 2 bay leaves
• 2 cups no-salt added beef broth
• 12-14 small cremini mushrooms