Chicken Tetrazini Southwestern Style

1 Preheat the oven to 450 degrees F.
2 Cover a 13 by 9 by 2-inch baking dish with butter.
3 Melt 1 tablespoon each of butter and oil in a frying pan over medium-high heat.
4 Sprinkle the chicken with salt and pepper.
5 Add the chicken to the hot pan and cook until pale golden and just cooked through, about 4 minutes per side.
6 Transfer the chicken to a plate to cool slightly.
7 Coarsely shred the chicken into bite-size pieces.
8 Meanwhile, add 1 tablespoon each of butter and oil to the same pan.
9 Add the onion, jalapeno, and garlic, and saute until the onion is translucent.
10 Add the wine and simmer for a minute or two.
11 Transfer the mixture into to the bowl with the chicken.
12 Melt 3 more tablespoons butter in the same pan over medium-low heat.
13 Add the flour and whisk for 2 minutes.
14 Whisk in the milk, cream, broth, and salt and pepper to taste.
15 Increase the heat to high and bring to a boil.
16 Simmer until the sauce thickens, whisking constantly.
17 Whisk in about 3/4  cup of the cheese.
18 Bring a large pot of salted water to a boil.
19 Add the spaghetti and cook until it is tender (a la dente)
20 Drain.
21 Add the pasta, sauce, and cilantro to the chicken mixture.
22 Toss until the sauce coats the pasta and the mixture is well blended.
23 Transfer the pasta mixture to the prepared baking dish.
24 Stir the remaining cheese and cornbread crumbs in a small bowl to blend.
25 Sprinkle the cheese mixture over the pasta.
26 Bake, uncovered, until golden brown on top, about 25 minutes.