Season the Chicken : In a small bowl, combine the garlic powder, sea salt, and black pepper. Pat the chicken breasts dry with a paper towel and sprinkle the seasoning mixture evenly over all sides.
Achieve the Initial Sear : Heat the avocado oil in your sauté pan over medium-high heat until it shimmers. Carefully place the seasoned chicken in the hot pan in a single layer, ensuring not to overcrowd it. Sear for 3–4 minutes on one side, until a deep golden-brown crust forms.
Build the Aromatic Base : Flip the chicken pieces. Scatter the diced shallots into the open spaces in the pan around the chicken. Cook for 1–2 minutes, stirring the shallots occasionally, until they soften and become fragrant.
Deglaze and Simmer : Pour the chicken broth into the pan. As it bubbles, use your tongs or a wooden spoon to gently scrape up any flavorful browned bits from the bottom of the pan. Bring the liquid to a steady simmer and cook for 2 minutes to allow the flavors to meld.
Create the Creamy Sauce : Reduce the heat to medium-low. Pour the heavy cream into the pan and gently whisk it into the broth. Allow the sauce to heat through, simmering gently for 5–7 minutes as the chicken continues to cook in the liquid.
Infuse Pesto and Tomato : Stir the basil pesto and julienned sun-dried tomatoes into the sauce until fully incorporated. Continue to simmer for another 2–3 minutes, allowing the sauce to thicken slightly and coat the chicken.
Confirm and Serve : Check for doneness by inserting an instant-read thermometer into the thickest part of a chicken breast; it should register 165∘F (74∘C). Remove the pan from the heat. Serve the chicken immediately, spooning the luscious sauce over the top and garnishing with torn fresh basil.
