With a sharp knife, slice the squash in half. If the squash is too tough, puncture in several places forming a dotted line around the squash. Microwave for 3-5 minutes to soften. Allow to cool before cutting in half.
Scoop out the seeds, brush with oil, and sprinkle with salt, and pepper. Bake for 40-45 minutes, or until a fork can easily pierce the skin.
Meanwhile, make the peanut sauce: combine the water, soy sauce, sesame oil, honey, lime juice, Sriracha, peanut butter, ginger, and garlic in a liquid measuring cup or medium bowl, stirring to combine.
Remove the squash from the oven and, with a fork, pull at the edges to produce that stringy “spaghetti” quality.
In a large bowl combine the “spaghetti” with the cucumber, carrots, bell pepper, green onion, onions, peanuts, cilantro, and the sauce. Add mixture back to the hollowed out spaghetti squash halves.