Saus Bawang Karamel

Bahan-bahan (12 porsi)

• 3 medium size yellow onions
• 2 tablespoons salted butter
• 2 teaspoons each salt and sugar
• 1/4 cup dry white wine
• 12 ounces sour cream
• 8 ounces cream cheese, softened
• 1 clove fresh garlic, grated (optional)
• fresh flat-leaf parsley, minced, to taste
• a few dashes of Worcestershire sauce or soy sauce (!!) to taste