Beef Stroganoff with Straw Potatoes

by Nadia Kim

8 servings

Mustard Sour Cream Sauce

• ¼ cupunsalted butter
• ¼ cupall-purpose flour
• 2 tspdry mustard powder
• 2 cupsbeef stock
• ½ cupsour cream

Beef

• ¼ cupunsalted butter
• 2small yellow onion
• 3 lbbeef tenderloin
• kosher salt
• black pepper

Straw Potatoes

• 4russet potatoes
• kosher salt
• 2 tbspparsley