Bring a large pot of water to boiling and add pepper halves for 8 minutes to soften. Meanwhile to a blender add tomatillos, cilantro and lime juice.
In a large skillet over medium high heat, saute the diced onion for one minute, add the ground turkey and cook until browned. While meat is cooking, steam the cauliflower in the microwave per package instructions.
Drain meat as needed. To the skillet add riced cauliflower and 2/3 cup of the tomatillo mixture from the blender. Stir and heat through for another minute.
Pour another 1/2 cup of the tomatillo mixture in the bottom of a casserole dish. Lay out the 8 poblano pepper halves. Scoop the meat and cauliflower mixture into each pepper half. Place in heated oven and bake for 15-20 minutes.