Bring a medium pot of salted water to a boil and cook the whole wheat penne according to package directions until al dente.
While the pasta cooks, slice the chicken breast into bite-sized strips and season evenly with sea salt and black pepper.
Heat the olive oil in a large skillet over medium-high heat. Add the chicken and sear until golden brown and cooked through, about 5-6 minutes.
Mince the garlic and add it to the skillet with the chicken, sautéing for 30 seconds until fragrant.
Add the baby spinach and julienned sun-dried tomatoes to the skillet, tossing until the spinach is just wilted.
Drain the pasta, reserving 2 tablespoons of the pasta water.
Add the cooked pasta, basil pesto, and reserved pasta water to the skillet.
Toss everything together over low heat until the pasta is well-coated and the sauce is creamy.
Serve immediately in a shallow bowl.