Preheat the oven to 400 degrees F. Prepare a rimmed baking sheet with parchment paper to roast the squash. Also, prepare an 8 x 11-inch baking dish with olive oil and set aside for the lasagna.

Drizzle the squash with 1 Tablespoon olive oil. Use your hands to rub the oil into the squash until glossy. Sprinkle the cut-side with 1/4 teaspoon sea salt. Place the squash cut side down on the prepared baking sheet and roast in the oven for 45 minutes or until very tender.

Meanwhile, to make the caramelized onions, add 1 Tablespoon olive oil to a large skillet over medium-low heat. Once the oil is shimmering, add the onions and 1/2 teaspoon sea salt. Toss the onions in the oil and spread the onions evenly in the pan with a spatula, cover, and scrape the pan every 5 minutes to ensure the onions start to brown and become very tender. Continue to scrape the pan with your spatula and cook until the onions are a deep brown color. Allow the onions to cook for 25 minutes or until the onions are browned and very tender.

Make the walnut ricotta by combining all the Walnut Ricotta ingredients in a mini food processor and puree until very thick and creamy. Season to taste with sea salt. Set aside.

Remove the squash from the oven and set aside to cool for 5 minutes or until it's cool enough to touch. Using a spoon, scrape out the squash flesh and transfer it to a large food processor with the sea salt and cumin. Discard the squash skin. Puree until the squash is creamy. Season to taste.

Lower the oven to 350 degrees F. Coat bottom of the prepared baking dish with 1/2 cup of the squash purée then two the lasagna noodles width-wise followed by the ricotta and onions and continue to layer until you use up all of the ingredients. The top layer should be the squash puree. Sprinkle the cumin over the top layer and add a few dollops of the walnut ricotta on top, if desired.

Transfer the lasagna to the oven, covered with parchment paper, for 50 minutes or until the noodles are tender. Remove from oven and set aside for 5 minutes before serving. Serve warm with fresh thyme or oregano garnished on top.

Store leftovers in a sealed glass container in the refrigerator for up to 4 days.