Spiralize the zucchinis and set them aside.

Heat 1 tablespoon of olive oil in a large skillet over medium heat. Add the spiralized zucchini noodles and sauté for 3-5 minutes until tender but still slightly crisp. Season with salt and pepper to taste. Remove from skillet and set aside.

Season the chicken breasts with salt and pepper on both sides. In the same skillet, add another tablespoon of olive oil and heat over medium-high heat. Cook the chicken for 6-7 minutes on each side until golden brown and cooked through. Remove from skillet and let rest for a few minutes.

If making homemade pesto, blend fresh basil leaves, garlic, pine nuts, Parmesan cheese, and olive oil in a food processor until smooth. Adjust seasoning with salt and pepper to taste.

Slice the rested chicken into bite-sized pieces. In the same skillet, return the sautéed zucchini noodles, add the sliced chicken, and pour the pesto sauce over the top. Toss gently to combine and heat through for 1-2 minutes.

Serve immediately, garnished with fresh basil leaves.