Prepare the vegetables: finely chop the yellow onion, mince the garlic, and chop the sweet potatoes, carrots, broccolini (or broccoli crowns), and zucchini into bite-sized pieces.
Heat 2 tablespoons of avocado oil in a very large skillet over medium-high heat until shimmering.
Add the chopped onion, minced garlic, sweet potatoes, and carrots to the skillet; stir to combine and cook briefly.
Add the chopped broccolini (or broccoli) to the skillet, stir, then add half of the spice mixture and half of the sea salt; stir to coat the vegetables.
Add the chopped zucchini, stir to combine, then cover the skillet and cook for 5 minutes over medium-high heat.
Uncover, stir, and cook an additional 3 minutes; test a sweet potato piece for doneness and continue cooking briefly if needed until vegetables are tender-crisp.
Meanwhile, heat the remaining 1 tablespoon of avocado oil in a separate large pot or Dutch oven over medium-high heat.
Add the chopped raw chicken to the hot pot, sprinkle with the remaining spices, sea salt, and black pepper, and let the chicken sit undisturbed for 3 minutes to brown.
Stir the chicken, cover the pot, and cook until the chicken is cooked through, about 8 minutes; then remove the cover and drain any excess liquid.
Portion the cooked chicken and vegetables into meal-prep containers according to desired portions.
