Make your dough by mixing the flours, 1/2 cup water, caraway seeds and salt until you get a dough that is soft and not too sticky or too dry. Add more water, up to 3/4 cup, in order to get the right consistency.
Roll the dough into two cylinders about 1 inch in diameter. Cover them with wet paper towels and set aside while you make the filling.
To make your filling, heat 1 tablespoon peanut oil or schmaltz in a medium sauté pan. Add onions and pickles and sauté until tender, about 3 minutes. Be careful as the pickle juices may splatter the oil. Then add pastrami and sauté until pastrami is warm, slightly crispy, and the fat has melted, about 5 more minutes.
To make the pot stickers, cut the dough into 1 inch pieces and roll them out into circles that are about 2 inches in diameter.
Put a dollop of filling into each pot sticker and secure each one. I used a fork to seal mine.
Heat some oil in a medium sauté pan over medium heat. Arrange 8 pot stickers on the pan. Pan-fry the pot stickers until the bottom turns light brown, about 2 to 3 minutes.
Add 2 tablespoons water to the pan and turn the heat to high. Cover the pan with a lid and let steam. Once the water evaporates, turn the heat back up to medium, flip the pot stickers, and fry until they are crispy and cooked through, about 3 more minutes, adding more oil if needed. Repeat for other pot stickers. Makes 16.
To make dipping sauce, whisk together dried mustard and water. Serve with pot stickers- be careful, it’s spicy!