Drizzle ½ tablespoon olive oil into each squash half.
Combine the spices, 1 teaspoon sea salt, and the pepper in a small bowl. Sprinkle this mixture evenly into the halves, using fingers to coat the flesh.
Place each squash half cut side down on a parchment-lined baking sheet and roast in the oven until squash is fork-tender (about 30 minutes).
While the squash is roasting, bring the water to a boil in a medium pot with 1 tablespoon olive oil and 1 teaspoon sea salt.
Add the rice to the pot and stir.
Reduce heat to a simmer, cover and cook for 50 minutes.
Turn off the heat and let the rice sit and steam for 5 minutes longer. Uncover, fluff with a fork, and cool slightly.
Place each baked squash half cut side up in a shallow baking dish.
Heat 1 tablespoon olive oil in a small sauté pan and add shallot, cooking until softened (about 5 minutes).
In a large mixing bowl, combine shallot, cooked rice, and walnuts. Add 1 tablespoon olive oil and mix thoroughly. Season with additional salt and pepper to taste.
Divide the rice mixture between each squash cavity. Drizzle each with the remaining tablespoon of olive oil.
Return the stuffed squash to the oven and bake for about 15 minutes until golden brown and heated through.
While the squash is baking, cut 4 slits in the pomegranate to create quarters.
Pull the quarters apart and carefully remove the seeds from the husk. Use gloves to prevent staining fingers from the juice.
Combine all ingredients for the relish in a medium bowl.
Remove baking dish from oven and top each squash half with some of the pomegranate relish. Serve immediately.