Bring a large pot of salted water to a boil and cook the pasta according to package directions until al dente. Reserve a cup of pasta water, then drain.

While the pasta cooks, season the chicken with a pinch of salt and pepper. Heat the olive oil in a skillet over medium-high heat and sear the chicken in a single layer until golden and cooked through, about 4–6 minutes per side depending on thickness. Transfer to a plate.

In the same skillet, add the garlic and a splash of pasta water to loosen any browned bits. Cook for about 30 seconds until fragrant.

Return the chicken to the pan and add the pesto, tomatoes, olives, and spinach. Stir until the spinach wilts and everything is coated in sauce.

Toss the drained pasta into the skillet with the sauce. If the mixture seems dry, add a bit more pasta water to reach your desired consistency.

Stir in the lemon juice and season to taste with salt and pepper. Finish with crumbled feta for a creamy, tangy finish.

Serve immediately with an extra drizzle of olive oil if you like and a handful of torn basil leaves for color.