1. Heat 1 tablespoon of olive oil in a large, deep skillet over medium-high heat. Season the chicken with salt and black pepper, then cook for about 3 minutes per side until lightly golden. Remove from the pan and set aside.

2. Add the remaining olive oil to the skillet along with the diced onion. Reduce the heat to medium and cook for about 5 minutes, stirring often, until soft and translucent.

3. Stir in the garlic, lemon zest, and dried tarragon. Cook for 1–2 minutes until fragrant.

4. Lower the heat and add the cream cheese to the pan. Slowly pour in the chicken broth, stirring constantly until smooth and creamy.

5. Mix in the cornstarch slurry and let the sauce gently thicken. Add a small squeeze of lemon juice.

6. Return the chicken to the pan and simmer on medium-low heat for 10–15 minutes, or until the chicken is fully cooked and tender. Add the remaining lemon juice during the final minute.

7. Meanwhile, cook the spaghetti in well-salted water according to package directions. Add the zucchini to the pasta water during the last minute of cooking, then drain.

8. Serve the creamy chicken over the spaghetti and zucchini. Finish with fresh basil and extra black pepper if desired.