Season & Sear Chicken: Pat the cubed chicken breasts dry with paper towels. Season evenly with 1/2 teaspoon salt and 1/4 teaspoon black pepper. Heat 1 tablespoon olive oil in a 12-inch cast-iron skillet over medium-high heat. Add chicken in a single layer and sear undisturbed for 4 minutes until deeply golden. Flip and cook for 2 more minutes until cooked through. Transfer chicken to a clean plate and set aside.

Pan-Toast the Gnocchi: In the same hot skillet, add the remaining 1 tablespoon olive oil. Add the uncooked potato gnocchi directly into the pan. Sauté over medium heat for 3 to 4 minutes, stirring occasionally, until the gnocchi develop crisp, lightly golden exterior blisters while staying pillowy soft inside.

Sauté Aromatics & Deglaze: Push the gnocchi to the outer edges of the skillet. Add the minced garlic and halved cherry tomatoes to the center. Sauté for 60 to 90 seconds until the garlic is aromatic and tomatoes begin to soften. Pour in chicken bone broth, scraping the skillet bottom with a wooden spoon to release all the rich caramelized fond.

Build Velvety Pesto Cream Sauce: Lower heat to medium-low. Pour in heavy cream and basil pesto, stirring until glossy and smoothly emulsified. Return the seared chicken and resting plate juices to the pan, add the baby spinach, and simmer gently for 2 minutes until the spinach wilts into the emerald sauce.

Melt Cheese & Garnish: Stir in grated Parmesan cheese until melted and velvety. Sprinkle shredded mozzarella over the top, cover with a lid for 1 to 2 minutes until bubbly and gooey. Remove from heat, garnish with fresh basil ribbons and cracked black pepper, and serve warm directly from the skillet.