Beef Stroganoff with Straw Potatoes

by Nadia Kim

4 servings

Mustard Sour Cream Sauce

• 2 tbspunsalted butter
• 2 tbspall-purpose flour
• 1 tspdry mustard powder
• 1 cupbeef stock
• ¼ cupsour cream

Beef

• 2 tbspunsalted butter
• 1small yellow onion
• 1.5 lbbeef tenderloin
• kosher salt
• black pepper

Straw Potatoes

• 4russet potatoes
• kosher salt
• 2 tbspparsley