- 1 For the Polenta, bring water and salt to boil in medium saucepan. Whisking constantly, add polenta in thin stream. Reduce heat to medium-low; stirring constantly, simmer about 7 minutes, or until thickened. Remove from heat.
- 2 For the Stroganoff, heat 2 tablespoons of the olive oil in large skillet on medium heat. Add onion and shallots; sauté about 4 minutes until softened. Add garlic and thyme; cook until lightly browned. Season with salt and pepper. Add mushrooms; cook about 5 minutes until softened and browned. Transfer mixture to large bowl; set aside.
- 3 Season steak with salt and pepper. Heat remaining 2 tablespoons of olive oil in same skillet. Add steak; cooking just until no longer pink. Transfer steak to bowl with mushroom mixture. Deglaze the pan with brandy, scraping to remove any brown bits from bottom of pan. Stir in stock and bring to a simmer. Add spinach leaves, cooking just until wilted. Return mushroom and steak mixture to the pan; cook and stir until heated through.
- 4 Serve Beef and Mushroom Stroganoff over Creamy Polenta. Garnish with sour cream, parsley and lemon zest and season with additional salt and pepper, if desired.