1. Preheat the oven to 350'F
2. In a large saucepan, cook the rotini to al dente (according to package directions without the salted water). A minute before the pasta is done, add the broccoli so it cooks a little. Reserve 1 cup of the pasta water, and drain the broccoli and pasta in the colander and set aside.
3. Dice the chicken into small 1/2 - 1 in pieces. While the pasta is cooking, add 1 Tbsp olive oil to a sauce pan. Cook the chicken completely so it's no longer pink inside and set aside.
4. Once you are done cooking the pasta, using the same pan melt the butter on the stovetop. Add the onions and cook for 4 minutes, then add the garlic and continue to cook for 1-2 minutes.
5. Add in the flour and stir well, absorbing all the butter and coating the onions and garlic in a thick white paste. Cook for 1 minute.
6. Add in the 1 cup of reserved pasta water. Whisk constantly to avoid lumps forming. Add the almond milk and increase the heat to medium high, bringing the sauce to a boil for 4-5 minutes.
7. As the sauce starts to thicken, add in the parmesan cheese and thyme and whisk to combine. Add the black pepper.
8. Cook at a simmer while stirring for 5-7 minutes, until the sauce becomes a creamy pourable consistency, like gravy.
9. Add the chicken, broccoli and pasta to the sauce. Stir to combine well.
10. Using pan spray, coat the bottom and sides of a 8x11 baking dish and add the pasta mixture to the dish.
11. Bake covered in the oven for 15 minutes, then uncover and allow the top to become crispy - about 10 more minutes. Remove from oven and allow to sit for about 5 minutes to firm up.