In a blender, combine the roughly chopped onion, garlic, and entire bunch of cilantro. Add 1/4 cup of the chicken broth to help it blend. Process until a smooth, green paste forms. Set aside.

Pat the chicken pieces dry and season generously with salt and pepper. Heat vegetable oil in a large Dutch oven over medium-high heat. Add the chicken, skin-side down, and sear for 5-7 minutes per side until deeply golden and crispy. Work in batches if necessary to avoid overcrowding. Remove chicken to a plate and set aside.

Reduce heat to medium. Add the ají amarillo paste and ground cumin to the pot, stirring constantly for 1 minute until fragrant. Pour in the cilantro base and cook for 3-4 minutes, stirring occasionally.

Add the rinsed rice to the pot and stir for 1 minute to coat it in the paste and lightly toast the grains.

Pour in the dark beer, using a wooden spoon to scrape up any browned bits from the bottom of the pot. Bring to a simmer. Stir in the remaining chicken broth, frozen peas, and diced carrots.

Return the seared chicken pieces to the pot, nestling them into the rice mixture. Increase heat to bring the liquid to a boil. Once boiling, immediately reduce heat to the lowest setting, cover tightly, and simmer for 20-25 minutes, or until the liquid is absorbed and rice is cooked.

Remove the pot from the heat and let it rest, still covered, for 10 minutes. Uncover, fluff the rice with a fork, and serve immediately.