2 tablespoons butter
1 medium onion, chopped
2 large stalks celery, chopped
2 large carrots, chopped
1/4 teaspoon salt
1/4 teaspoon black pepper
2 large cloves garlic, minced
2 tablespoons lemon juice
4 tablespoons all-purpose flour
4 cups (.95 L) low-sodium chicken or vegetable stock, warmed
1/2 teaspoon Worcestershire sauce
1/4 teaspoon ground mustard powder
1/4 teaspoon smoked paprika
6 oz (180 g) smoked Gouda, shredded
2 oz (60 g) sharp Cheddar, shredded
Fresh parsley, for garnish (optional)