I start by placing fresh poblano peppers on a baking sheet, skin-side up, and broiling them for 6–10 minutes until the skins blister and char. Once roasted, I pop them into a sealed plastic bag for 5 minutes to steam, making the skins easy to peel. Then, I dice them and set them aside.
I boil my pasta in salted water for about 75% of the recommended cooking time. This way, it finishes cooking in the oven and absorbs the sauce better. After draining, I drizzle a little olive oil on it to keep it from sticking.
In the same pot, I melt butter over medium heat and whisk in flour to form a roux. I slowly add heavy cream, whisking constantly until smooth and slightly thickened.
Then I stir in mustard powder, mascarpone, gouda, white cheddar, and sharp cheddar until the sauce is creamy. I mix in the roasted poblanos, Cajun seasoning, cayenne, smoked paprika, salt, and black pepper.
I combine the pasta and cheese sauce, then pour it all into a greased baking dish. I sprinkle panko breadcrumbs evenly on top for crunch. It bakes at 350°F for 15–20 minutes until bubbly, then I broil it for 2–3 minutes to get that perfect golden crust.
I let it rest for 5 minutes so the sauce settles before serving. That first cheesy, smoky bite always makes me smile.