Dice the onion into 1/4-inch pieces, seed and dice the poblano peppers into 1/2-inch pieces, mince the garlic, and cut the chicken into 1/2-inch cubes. Bring a large pot of salted water to a boil and cook the pasta until just al dente (about 2 minutes under the package time), then drain and set aside. I like to slightly undercook the pasta here since it will continue cooking in the chili sauce, which keeps it from getting mushy.

Heat 3 tablespoons butter in a large pot over medium-high heat until foaming. Add the diced chicken and cook for 4-5 minutes, stirring occasionally, until the pieces are browned on all sides. Remove the chicken to a plate, then reduce heat to medium and add the diced onion and poblano peppers to the same pot, scraping up any browned bits. Sauté for 5-7 minutes until softened, then add the minced garlic and cook for another minute until fragrant.

Add the cumin, smoked paprika, and chili powder to the pot and stir constantly for about 1 minute to toast the spices and release their oils. Pour in the chicken broth, salsa verde, and green chilies, stirring well to combine. Return the cooked chicken to the pot and add the drained white beans. Bring the mixture to a gentle simmer and cook for 5 minutes to allow the flavors to meld.

Stir the cooked pasta from Step 1 into the chili mixture, breaking up the cream cheese into small pieces and adding it to the pot. Stir constantly over medium heat for 2-3 minutes until the cream cheese is completely melted and incorporated, creating a smooth, creamy sauce. I prefer to use room-temperature cream cheese because it melts more evenly without creating lumps in the sauce.

Remove the pot from heat and stir in the shredded cheese until completely melted and the dish is creamy and well combined. Taste the chili mac and cheese and adjust seasoning with salt and black pepper as needed. The salsa verde and green chilies provide good base flavor, so add salt gradually to avoid over-seasoning.

Ladle the white chicken chili mac and cheese into bowls and top generously with chopped green onions and fresh cilantro. Serve immediately while hot and creamy.