Preheat oven to 350 degrees. Slice ends from squash & discard. Cut in half. Using a spoon, scoop out the seeds from the center. Season the inside with salt & pepper. Bake cut side down on a parchment paper (or aluminum foil) lined baking sheet. Bake for 30-45 minutes, depending on how big your squash is. Let cool until you can safely handle it.
While the squash is cooking, sauté the onion & jalapeño in the extra virgin olive oil until the onions are translucent. Add the garlic & cook for an additional minute, or until the garlic is fragrant. Remove from the heat & season with salt and pepper.
Using a fork, gently scrape out the insides of the cooled spaghetti squash into a large bowl - reserving the shell. In that same large bowl, combine the spaghetti squash insides with the cooked chicken & the sautéed onion, jalapeños & garlic. Stir in the Frank's Red Hot Sauce.
Scoop the mixture back into the empty spaghetti squash shells. Bake at 350 for 15 minutes. Drizzle with {Whole30} Ranch & sprinkle with a generous portion of chopped green onions.