In a large skillet over medium-high heat, melt butter. Add onion, garlic and sauté about 3 minutes or until softened. Add chorizo/sausage, red pepper and cook together for 5 minutes or until chorizo is golden brown.
Add beer, lime juice, mustard and mussels to the skillet. Lightly sprinkle the diced cabbage on top and cover. Once covered, steam and over medium heat for 5 to 7 minutes until mussels open. Stir in chopped parsley, add salt and pepper to taste.
Serve immediately, yields 4-6 servings.