Slow N' Easy Short Ribs

Ingredients

• 3 pounds beef short ribs, bone-in
• 1/2 teaspoon salt, plus more, to taste
• 1/2 teaspoon pepper, plus more, to taste
• 1 tablespoon canola oil
• 4 medium carrots, cut into 1-inch pieces
• 1 cup beef broth
• 4 fresh thyme sprigs, plus more, to taste, chopped, for garnish
• 1 bay leaf
• 2 large onions, cut into 1/2-inch wedges
• 6 cloves garlic, minced
• 1 tablespoon tomato paste
• 2 cups dry red wine or beef broth
• 4 teaspoons cornstarch
• 3 tablespoons cold water
• mashed potatoes, optional, to taste, cooked and warm, for serving