Maxwell Street Polish Tartlets - Pepperidge Farm

Ingredients

• 3 tablespoons butter
• 1 large onion, cut in half and thinly sliced (about 2 1/2 cups)
• 1/8 teaspoon garlic powder
• 1 dash ground black pepper
• 1 teaspoon sugar
• 1/2 of a 17.3-ounce package Pepperidge Farm® Puff Pastry Sheets(1 sheet), thawed
• 5 ounces (about 1/3 of a 16-ounce package) kielbasa, cut in half lengthwise and sliced 1/4-inch thick
• 2 tablespoons yellow mustard
• 1 tablespoon chopped fresh parsley