Preheat the oven to 400°F. Place a cast iron skillet in the oven to preheat.
Bring a large pot of water to a boil. Add the poblano peppers and boil for 10 minutes to soften the skins. Remove from the water and let cool slightly. Slice the peppers open, rinse under cold water, remove the seeds, and set aside.
Heat a skillet over medium heat and add the oil and onions. Cook for about 5 minutes, until softened. Add the ground antelope and cook until browned. Season with cumin, coriander, garlic powder, Mexican oregano, and salt. Remove from heat.
In a large bowl, combine the cooked meat mixture, shredded cheese, cream cheese, cooked quinoa (or rice), cilantro, and salsa. Divide the filling evenly and stuff each poblano pepper. Top with additional shredded cheese.
Carefully place the stuffed poblano peppers into the preheated cast iron skillet and bake for 30–35 minutes. Optional egg variation: About 15 minutes into baking, crack an egg into the center of each stuffed pepper and return to the oven until the whites are set but the yolks remain slightly runny.
Serve each stuffed pepper with sliced avocado, sour cream, and salsa.