Preheat large skillet on medium-high heat and swirl 1/2 tablespoon of olive oil. Add bell peppers and onion, sprinkle with salt and pepper and cook for 3 minutes, stirring twice. Transfer to a large bowl.
Return skillet to heat and add another 1/2 tablespoon of oil, zucchini and sprinkle with salt and pepper. Cook for 4 minutes, stirring twice. Transfer to a bowl with peppers.
Return skillet to heat, add grape tomatoes and cook for 2 minutes, until blistered a bit. Transfer to a bowl with peppers and zucchini.
Return skillet to heat and add remaining 1 tablespoon of oil to coat. Add chicken, sprinkle with salt and pepper and cook for 10-12 minutes, stirring only a few times and allowing to brown. Add 3 tablespoons of pesto and stir.
Add previously cooked bell peppers, zucchini, grape tomatoes and remaining 3 tablespoons of pesto. Stir and cook for another minute.
Serve garnished with Parmesan cheese on its own or with arugula, rice or pasta.
Video
Notes
Store: Store leftovers in an airtight container in the fridge for up to 5 days.
Reheat: Reheat in a microwave or on the stove with a bit of water or broth until heated through.
Freeze: Chicken does freeze well but not the veggies.