Fill a large pot with water and bring to a boil. Once boiling, add 2 tablespoons of salt to the water and add your angel hair pasta. Cook according to the package directions so that the pasta is al dente. Drain and set aside.
While you're waiting for your water to boil, heat a large flat bottomed pan on medium heat with 2 tablespoons of avocado oil, or any high heat oil.
Slice chicken breasts in half lengthwise to yield thinner, flatter breasts. Season with salt and pepper.
Place all purpose flour in a bowl and dredge chicken breasts in the flour, shaking off any excess.
Place chicken into pan and cook for about 3-4 minutes on each side, until golden brown and cooked through to 165 degrees at the thickest part and remove from pan.
If the pan is dry, add 1 more tablespoon of olive oil before adding sliced shallots and asparagus pieces. Saute for about 3 minutes, or until the vegetables are softened slightly. Then add minced garlic, sundried tomatoes, Italian seasoning, red pepper flakes, and cook for 2 more minutes or until garlic is fragrant but not burning.
Deglaze the pan by adding 3/4 cup of chicken stock to the pan and stirring up the little bits that are stuck to the bottom of the pan. Then add the 3/4 cup of heavy cream and stir together.
Cook until the sauce is starting to bubble and thicken enough to lightly coat a spoon, about 4-5 minutes.
Add your spinach and parmesan cheese to the sauce and cook until wilted, about 1 minute. Turn off the heat.
Slice your chicken into thin strips and return chicken to the pan (along with any juices) along with the angel hair pasta. Let the chicken and pasta warm back up in the saucefor 2 minutes before serving.