1. Heat oven to 425 degree F. Combine oil, garlic, lemon peel, 1/2 teaspoon salt, 1/2 teaspoon black pepper, and the red pepper in large bowl. Add potatoes, tossing to coat. Spread potatoes evenly in jelly-roll pan. Cover top tightly with foil and bake 40 minutes.
2. Meanwhile, brown sausage in large skillet over medium-high heat, 5 minutes. Remove with slotted spoon; drain on paper towels. Add onion to drippings in skillet; cook until browned, 2 minutes. Add kale and pinch salt and pepper; cook 2 minutes. Remove from heat. Stir in ricotta.
3. Uncover potatoes and cool slightly. Arrange one third of the potatoes evenly in shallow 2-quart baking dish. Layer with half of the kale mixture, half of the sausage and half of the mozzarella, then another third of the potatoes and remaining kale, sausage, and mozzarella. Pour on chicken broth. Top with remaining potatoes; sprinkle with Parmesan. Bake, uncovered, 20 minutes. Let stand 5 minutes before serving. Makes 6 servings.