INGREDIENTS
•
2 tablespoons unsalted butter
•
2 small yellow onions, cut into 1/4-inch dice (about 2 cups)
•
1 teaspoon kosher salt
•
1 cup warm water (105 to 115 degrees F)
•
1 package active dry yeast
•
2 3/4 cups bread flour, plus more for dusting
•
1 teaspoon granulated sugar
•
2 teaspoons vegetable oil, plus more for greasing
•
1/4 cup pretzel salt or other coarse salt
•
1 tablespoon caraway seeds, lightly crushed
•
1/4 cup baking soda
•
German mustard, for serving, optional