Bring a large pot of water to a boil and cook the whole wheat pasta according to package directions until al dente.
While the pasta cooks, season the chicken breast with sea salt and black pepper on both sides.
Heat a large non-stick skillet over medium-high heat and cook the chicken breast until golden brown and cooked through, approximately 6 minutes per side.
Remove the chicken from the skillet and let it rest for 3 minutes before slicing into thin strips.
In the same skillet, add the minced garlic and sun-dried tomatoes, sautéing for 1 minute until the garlic is fragrant.
Add the baby spinach to the skillet and stir for 1 minute until it just begins to wilt.
Drain the cooked pasta, reserving 2 tablespoons of the cooking water, and add the pasta to the skillet.
Add the sliced chicken, basil pesto, and lemon juice to the pan, tossing everything together until well coated.
If the sauce is too thick, add the reserved pasta water 1 tablespoon at a time until the desired consistency is reached.