Heat the avocado oil in a large skillet over medium-high heat until shimmering.
Add the diced chicken breast to the skillet and cook until browned on all sides, approximately 5 minutes.
Stir in the diced onion, green bell pepper, and celery, sautéing for another 4 minutes until the vegetables are tender.
Add the smoked paprika, garlic powder, onion powder, dried oregano, sea salt, and black pepper, stirring constantly for 1 minute to toast the spices.
Pour in the diced tomatoes with their juices and bring the mixture to a gentle simmer.
Add the shrimp to the skillet and cook for 3 to 4 minutes, or until they are pink, opaque, and cooked through.
Fold in the cooked brown rice and stir until the rice is heated through and has absorbed the flavors of the sauce.
Remove from heat, garnish with freshly chopped parsley, and serve warm.