Preheat oven to 425 degrees F. Prepare two rimmed baking sheets with parchment paper.

Place the Spaghetti squash on a flat surface and slice it in half with a sharp knife lengthwise. Remove the seeds and discard seeds. Drizzle with 2 Tbsp. olive oil and sprinkle with sea salt and pepper, then place the two squash halves cut side down on one of the prepared baking sheets and roast in the oven for 30 minutes or until very tender. Remove from the oven; set aside to cool then use a fork to remove the 'spaghetti strands' from the outer shell of the squash. Discard the outer shell of the squash.

Place the cauliflower on one of the prepared baking sheets and drizzle with 1 Tbsp. of the oil and sprinkle with sea salt and pepper; toss to combine.

Place the cauliflower in the oven and roast for 20 minutes; toss the cauliflower around half way through roasting. Then remove from the oven and set aside.

Meanwhile, puree the tahini, lemon juice, water, garlic, sea salt and pepper to taste in a blender until you reach the desired dressing consistency.

On a large platter or in a large bowl, combine the roasted cauliflower, roasted Spaghetti squash, Swiss chard and drizzle with the tahini dressing; toss gently to combine. Add pecans and serve immediately.