Bring a large pot of water to a rolling boil. Salt the water and add the chicken breasts, Cook for 25-30 minutes, until the chicken breasts are cooked through.
Preheat the oven to 400F. Use a sharp knife to poke a hole in the center of the spaghetti squash. Microwave for 5 minutes - this will make it super easy to cut the squash in half, Use the hole as a starting point to hut the squash in half lengthwise.
Scrape out the seeds from the center of each half. Place the squash facedown on a baking sheet lined with aluminum foil. Bake for 30-40 minutes, until browned and tender. The squash will appear visibly softer.
While the squash cooks, put the cooked chicken breast in a large bowl with the red hot sauce, Greek yogurt, jalapenos, and onions. Use a hand mixer to shred the chicken until it is completely shredded and loose. Stir in the green onion, Parmesan cheese and mozzarella pearls.
Remove the squash from the oven and flip over so the flesh side is facing up. Loosen the stringy insides of each half then pile on the buffalo chicken mixture. Gently press into the squash. Place an aluminum tent over the squash and place back into the oven for an additional 25-30 minutes - uncover for the last five minutes of cooking.
Serve each half alongside some fresh celery and top with blue cheese crumbles, Parmesan cheese and fresh parsley, as desired. Enjoy!