Preheat oven to 180°C. Place baguette slices on a baking tray. Spray with olive oil spray. Bake for 5 minutes or until light golden. Meanwhile combine sour cream and horseradish cream in a small bowl. Season with salt and pepper. Set aside. To serve, spread each baguette slice with a little sour cream mixture, and top with a strip of roast beef. Garnish with a basil leaf. Season with cracked black pepper and arrange on a serving platter.