Silky, peppery butter beans coated in a creamy Parmesan sauce and crowned with a shatteringly crisp Parmesan tuile. Comforting yet bright with toasted black pepper, this quick, high-protein dish delivers rich flavor in minutes.
Preheat oven to 400°F (205°C).
Toast the peppercorns: Add whole black peppercorns to a large dry skillet over medium-low heat and toast, shaking often, until fragrant, 3 to 5 minutes. Remove from heat and let cool.
Make Parmesan crisps: Line a large baking sheet with parchment. Divide 1/3 cup of the grated Parmesan into 2 thin circles, leaving at least 1 inch (2.5 cm) between them; top with freshly ground black pepper. Bake until golden-brown and crisp, 5 to 8 minutes. Let cool on the sheet.
Crush the peppercorns: Transfer cooled peppercorns to a resealable bag and crush with a rolling pin into coarse pieces (about the size of coarsely ground pepper).
Cook aromatics: Return the large skillet to medium heat. Melt the butter, then add minced garlic and the crushed peppercorns. Cook, stirring continuously, until the garlic is pale golden, 1 to 2 minutes.
Build the sauce: Add the butter beans with their liquid and the fine sea salt. Increase heat to bring to a bubble, then reduce to medium and simmer, stirring occasionally, until the liquid reduces by half, about 10 minutes.
Thicken: Whisk cornstarch and water in a small bowl until completely smooth. Stir the slurry into the skillet and cook, stirring, until the sauce thickens and turns silky, 1 to 2 minutes.
Finish with cheese: Stir in the remaining 1/3 cup grated Parmesan until melted and smooth. Taste and adjust salt and pepper as needed.
Serve: Divide beans into 2 bowls. Garnish with additional freshly ground black pepper and extra Parmesan if desired. Top each bowl with a Parmesan crisp and serve immediately.