Latvian Bacon Buns (Pîrâgi) Recipe - Traditional Dish from Latvia

Ingredients

• 1 finely chopped onion
• 0.5 - 0.75 lb (340 g) bacon, finely diced (or 0.5 lb (227 g) bacon and 0.25 lb ham or pork jowl)
• salt and pepper to taste
• 0.75 cup milk
• 0.25 cup butter
• 2 tsp salt
• 2 tbsp sugar
• 3 1 pkg. (about 1 tbsp) dry yeast
• 0.25 cup warm water
• 1 beaten egg
• 3.5 cup white flour
• 1 - 2 tbsp sour cream (optional)
• 1 egg, beaten
• 1 - 2 tsp milk or water (optional)
• 0.25 tsp sugar (optional)