I recommend letting the chicken sit out until it is ready to cook. Letting it come slightly to room temp will shorten the cooking time, provide an even cook, and thus maintain moisture, providing a juicy, perfectly cooked chicken breast. In a large saucepan or Dutch oven, bring water and salt to a boil. Cut a 2” piece of jalapeño pepper and finely mince it to make about 1 tablespoon of minced jalapeño.
Use this time to shred the cheddar cheese and jalapeño slices that will be added as a finishing touch. When the pasta is done, pour into a colander and place under running cold water. Return the pan to the stovetop over high heat. Add the butter to the pan with ½ of the Italian seasoning and the minced garlic.
Slowly incorporate the heavy cream and milk into the sauce. Whisking constantly to prevent lumps. Once the milk and cream are fully incorporated, reduce the heat to low and stir in the shredded asiago cheese and cayenne pepper. Stir until melted, about 1 minute. Add the pasta to the cheese sauce and toss to coat. Turn off the heat and cover. Thinly slice the chicken breast. Add the chicken, shredded cheddar cheese, and jalapeño slices to the pasta.
Transfer any leftovers into an airtight container once the rattlesnake pasta has completely cooled. Then store it in the fridge to enjoy for up to 3 to 4 days.