Pasta Krim dengan Kubis Napa dan Bacon

Bahan-bahan (4 porsi)

• 1 onion ((8.8 oz, 250 g))
• ½ lb napa cabbage ((about ½ small head))
• 4 button mushrooms ((sliced, 106 g))
• 4 slices applewood smoked bacon
• 1 lb penne pasta ((4 oz, 113 g per person))
• 4 Tbsp unsalted butter ((¼ cup))
• 5 Tbsp all-purpose flour (plain flour)
• 2 cups whole milk ((or use reduced-fat milk))
• ½ tsp Diamond Crystal kosher salt
• ⅛ tsp freshly ground black pepper
• 2 oz Parmigiano-Reggiano or Parmesan cheese ((½ cup; shredded or freshly grated))
• 2 oz Gruyere cheese ((½ cup; freshly grated))
• ¼ cup panko (Japanese breadcrumbs) ((4 Tbsp))
• parsley ((fresh; finely chopped))