Crockpot Short Rib Bourguignon

Bahan-bahan (6 porsi)

• 2 yellow onions, thinly sliced
• 5 pounds bone-in beef short ribs
• kosher salt and black pepper
• 6 shallots, halved
• 8 g arlic cloves, smashed
• 6 carrots .chopped
• 1 bottle (750ml) (or 3 cups) dry red wine, such as Pinot Noir
• 2 cups beef broth
• 1/2 cup cognac or brandy ((optional))
• 2 tablespoons tomato paste
• 2 tablespoons chopped fresh thyme
• 2 dried bay leaves
• 4 tablespoons salted butter
• 2 cups sliced cremini mushrooms
• 1 tablespoon chopped fresh sage