German Onion Pie

Ingredients

• 1 ¾ cups all-purpose flour
• ¼ cup butter
• 1 packet active-dry yeast (about 4 grams)
• 1 teaspoon salt
• 1 teaspoon granulated sugar
• ⅔ cup lukewarm milk
• 4 medium yellow onions (about 500 grams)
• ¼ cup butter (for cooking onions, plus additional for greasing)
• 1 tablespoon all-purpose flour
• 2 large eggs
• ⅓ cup heavy cream
• 2 slices thick-cut bacon (diced)
• 1 teaspoon caraway seeds (optional, as used by my Oma Sieghilde)