Catalan Style Beef Stew (Estofado a la Catalana)

Ingredients

• 2 tablespoons olive oil
• 2 lbs. 900 grams chuck steak (filete de aguja)
• 0.5 lbs. 230 grams pancetta (or thick-cut bacon)
• 1 yellow onion (finely chopped)
• 4 garlic cloves
• 1 tablespoon all-purpose flour
• 1 cup dry red wine
• 1 sprig parsley
• 1 bay leaf
• 1 teaspoon dried oregano
• 1 cup beef broth (or water)
• 0.4 lbs. 200g button mushrooms
• Salt and pepper to taste
• ½ teaspoon finely grated dark chocolate
• ¼ teaspoon cinnamon
• ¼ teaspoon nutmeg
• 2 large potatoes
• 1 large Butifarra sausage (around 150 grams/ 5oz.)