Filet of Beef Stroganoff

Ingredients

• 2 beef filets about 4 to 5 ounces each, trimmed of all fat and sinews
• 1 ½ teaspoons Spanish paprika
• Fine sea salt
• 2 tablespoons unsalted butter
• 2 ½ tablespoons olive oil
• 1 ½ cups coarsely julienned mushrooms
• Freshly ground black pepper
• 2 tablespoons medium or amontillado sherry
• ⅓ cup sour cream or crème fraîche
• 2 cups ¾-inch cubed zucchini
• 2 tablespoons chopped chives