Heat the oven to 400 degrees.
Season the chicken pieces with about 1 teaspoon each salt and pepper, plus a pinch of crushed red pepper.
Place a large Dutch oven or other heavy-bottomed pot over medium-high heat and add oil. Let oil heat up for a few minutes. Add the chicken and cook, stirring, until the chicken is slightly browned but not fully cooked through, about 5 minutes. Remove from the pot and set aside.
Add the onion, garlic and about 1 teaspoon each salt and pepper to the pot. Cook over medium-low heat, scraping browned bits from the bottom of the pan, until garlic is fragrant, 2 to 3 minutes. Turn the heat up to high. Add the rice, broth and pesto to the pot; stir to combine. Cover until it comes to a boil, 3 to 5 minutes.
Remove the pot from heat and stir the chicken and any juices into the rice. Place the pot, covered, into the oven and bake until the rice and chicken are fully cooked, about 20 minutes.
Remove the pot from the oven and stir in the peas. Cover and let sit for 5 minutes before serving, allowing the peas to cook and the rice to get creamy.
Serve topped with fresh basil, a squeeze of lemon and more pesto.
