Place whole poblano peppers under a broiler or on a hot grill until skins char evenly.
Transfer them to a covered bowl or bag to steam for easier peeling.
Peel skins, remove seeds, and dice peppers once cooled.
Bring a large pot of salted water to a boil and cook pasta until al dente.
Drain pasta but reserve a little pasta water in case sauce needs thinning later.
Set cooked pasta aside while preparing cheese sauce.
Melt butter in a saucepan, whisk in flour, and cook briefly to remove raw taste.
Slowly whisk in milk and cream until smooth and thickened.
Add smoked gouda, cheddar, and seasonings until sauce melts smoothly.
Stir diced poblano peppers into the cheese sauce evenly.
Add cooked pasta and fold gently so every piece is coated.
Adjust seasoning and consistency if needed before baking or serving.
Transfer mixture to a greased baking dish and top with breadcrumbs.
Bake at 375°F for 15 minutes until bubbly and golden on top.
Let rest briefly before serving for best texture.