Pat the chicken breasts dry and season them generously with salt and pepper on both sides.
Warm a tablespoon of olive oil in a skillet over medium-high heat until it shimmers and just begins to smoke slightly.
Place the chicken breasts in the hot skillet, laying them away from you to prevent splashes, and sear for about 5-6 minutes per side until golden brown and cooked through. You should see a nice crust forming and hear a steady sizzle.
Remove the chicken from the skillet and set aside on a plate to rest, allowing the juices to redistribute.
Add the remaining tablespoon of olive oil to the same skillet over medium heat. Toss in the minced garlic and cook for about 30 seconds until fragrant, making sure it doesn’t burn.
Add the sliced zucchini and squash to the skillet, spreading them out evenly. Let them cook undisturbed for 2-3 minutes until they start to soften and develop some caramelized edges with a slight browning.
Shake the skillet or stir the vegetables gently to mix them with the garlic and allow them to cook for another 3-4 minutes until tender but still retaining a slight crunch. The vegetables will look glossy and gently browned.
Sprinkle the lemon zest over the vegetables, giving everything a quick stir to release bright citrus aroma and flavor.
Slice the rested chicken breasts into thick strips and serve them on a plate alongside the sautéed zucchini and squash.
Optionally, season with additional salt and pepper to taste, and garnish with more lemon zest or fresh herbs for extra brightness.
