1. Preheat the oven to 200°C.
2. Melt 100 g butter in a pan over medium-low heat.
3. Add 100 g plain flour and stir continuously until the flour cooks out and the roux thickens and darkens slightly.
4. Add 500 ml milk a little at a time, whisking after each addition, until the béchamel is smooth and thick.
5. Stir in 1 pinch ground nutmeg.
6. Take off the heat and stir in the grated Gruyère and cheddar until melted.
7. Cook 350 g bronze cut pasta shells in salted boiling water for 4–5 minutes less than the packet says so they stay firm (they will finish cooking in the oven), then drain.
8. In an oven dish, mix 100 ml Chimac creamy buffalo sauce, the cheesy béchamel and the pasta shells until everything is well coated.
9. Scatter 50 g breadcrumbs over the top and bake at 200°C for 20 minutes, or until irresistible looking.
