Guinness-Venison stew - Jeffery Deaver

Ingredients

• 3 tablespoons olive oil
• 1 quart of buttermilk
• 3 pounds venison loin, with fat and silverskin removed, cut into 1 ½ inch cubes
• 3 large yellow onions, chopped
• 2 cups baby carrots
• 2 large Idaho potatoes, peeled and cut in 1 ½ inch cubes
• 2 tablespoons minced garlic
• 3 bottles of stout, like Guinness (12-ounce bottles)
• 5 cups beef stock
• 3 tablespoons dark brown sugar
• 1 teaspoon Worcestershire sauce
• 2 bay leaves
• 2 tablespoons fresh thyme, chopped fine
• Olive oil
• Cayenne pepper
• Salt
• Pepper
• Butter as needed
• All-purpose flour as needed