Flank Steak with Potatoes, Spicy Greens, and Herbed Horseradish | Easy Home Meals

Ingredients

• 3/4 cup sour cream
• 2 Tbsp. mayonnaise
• 2 Tbsp. prepared horseradish (not horseradish sauce)
• 2 Tbsp. snipped fresh chives
• 1 tsp. white wine vinegar
• 1 garlic clove, grated
• 1/4 tsp. kosher salt
• 1 lb. fingerling potatoes (may use refrigerated potatoes)
• Kosher salt and Freshly Ground Black Pepper
• 2 tbsp. canola, grapeseed, or peanut oil, divided
• 1 (2-lb.) flank steak
• 2 packed cups spicy baby greens (such as arugula or watercress)
• 1 lemon halved, for serving