Preheat oven to 410°F. Line a cookie pan with parchment paper.
Poke a few holes in each squash half, drizzle with 1 tbsp of olive oil, sprinkle with salt, 1 tsp cinnamon, and 1 tsp nutmeg.
Bake squash halves upside down for 25 minutes.
While squash bakes, heat 2 tbsp olive oil in a sauté pan over medium heat. Add chopped red onion and cook for 5 minutes until soft.
Add plant-based mince or cooked brown lentils to the pan and sauté for 10 minutes until browned.
Add chopped sweet potatoes, mushrooms, and minced garlic, followed by remaining cinnamon, black pepper, and nutmeg. Sauté for another 10 minutes.
Add chopped kale and cranberries, simmering over low heat for 5-8 minutes. Add salt to taste.
Remove from heat and stir in 3/4 cup of cooked quinoa or couscous.
Carefully remove squash from the oven and turn the halves right side up. Stuff each half generously with the prepared mixture.
Lower oven temperature to 350°F and bake the stuffed squash for another 10 minutes before serving.