Beef Stroganoff with Straw Potatoes

by Nadia Kim

12 servings

Mustard Sour Cream Sauce

• 89 mlunsalted butter
• 89 mlall-purpose flour
• 15 mldry mustard powder
• 710 mlbeef stock
• 175 mlsour cream

Beef

• 89 mlunsalted butter
• 3small yellow onion
• 2040 gbeef tenderloin
• kosher salt
• black pepper

Straw Potatoes

• 4russet potatoes
• kosher salt
• 30 mlparsley