Preheat oven to 350 degrees. Halve and clean out the seeds.
Place the halved squash on a parchment or silpat lined baking sheet, flesh side down. Bake for 30 minutes, until tender. While the squash is cooking, prep the tempeh.
Crumble the tempeh into a bowl and cover with soy sauce and 1 cup vegetable broth. Let marinade for 30 minutes.
In a large skillet, heat 1 tbsp. oil over medium heat. Add the chopped onion and cook for 5 minutes. Add in the garlic, fennel seeds, thyme, rosemary, red pepper flakes and sage. Stir until combined. Drain the tempeh and add to the skillet. Cook for 15 minutes until golden and crispy.
Once the tempeh sausage is done, add in the kale and remaining 1/2 cup vegetable broth. Cook until kale is wilted.
Stuff the kale and tempeh mixture into each of the squash halves.
Top with finely chopped walnuts.Turn on the broiler and place the squash halves underneath the broiler until just browned, about 3-4 minutes.Serve hot!