Chop the bacon into 1/2-inch pieces and fry in a skillet over medium-high heat until crispy, about 8-10 minutes, stirring occasionally. Transfer to a paper towel-lined plate to drain. While the bacon cooks, fill a large pot with salted water and bring it to a boil—this takes about 10 minutes and will be ready when you need it for the pasta.

Once the water reaches a rolling boil, add the pasta and cook according to package directions until al dente, usually 8-10 minutes. Drain well and set aside—I recommend keeping a little starchy water nearby as it helps the sauce coat the pasta more evenly if needed. Do not rinse the pasta.

Heat a cast-iron skillet or griddle over high heat until it just begins to smoke, about 3-4 minutes. Toss the chicken cubes with 3 tablespoons of butter until lightly coated, then generously coat with the blackening seasoning on all sides. Working in batches if needed, sear the chicken on the hot griddle for 5-7 minutes total, stirring occasionally, until deeply browned and cooked through. The chicken should be caramelized and fragrant with charred edges.

In a large saucepan, melt 3 tablespoons of butter over medium heat. Add the flour and whisk constantly for about 1 minute to create a smooth roux—this cooks out the raw flour taste and ensures a silky sauce. Pour in the cream and milk slowly while whisking to avoid lumps, then continue cooking and stirring until the mixture thickens slightly, about 2-3 minutes.

Reduce heat to low and add the hand-shredded cheddar cheese a handful at a time, stirring gently until fully melted between additions—shredded cheese melts more smoothly than blocks and creates a creamier sauce. Once the cheese is fully incorporated, stir in the garlic powder and dry mustard powder. I find that the mustard powder adds a subtle depth that balances the richness of the cheese beautifully.

In a large bowl, gently toss the cooked pasta with the cheese sauce from Step 5, the crispy bacon from Step 1, and the peas. If the mixture seems thick, add a splash of the reserved pasta water to loosen it. Transfer to serving bowls or plates, top each portion with the blackened chicken from Step 3, and finish with the sliced scallions. The warm pasta will soften the scallions slightly while keeping them fresh and bright.