Preheat oven to 375°. Cut squash in half from top to bottom. Remove pulp and seeds.
Place squash halves on a sheet pan cut-side up. Sprinkle with ½ tsp salt, ¼ tsp pepper, and cumin. Drizzle with about 1 tbsp olive oil and rub onto the interior of the squash.
Turn squash cut-side down on sheet pan and bake for 40 minutes.
Heat 1 tbsp olive oil in a large skillet over medium heat. When hot add onions, garlic, and rosemary and cook briefly until fragrant. Add ground lamb and a pinch of salt and pepper. Cook, stirring occasionally, until no longer pink. Remove to a bowl or plate.
Add 1 tbsp olive oil to skillet, then add mushrooms, kale or chard, and a pinch of salt and pepper to skillet. Cook, stirring occasionally, for 5-7 minutes or until softening. Remove from heat.
Return onion and lamb mixture to the pan. Add Parmesan cheese and lemon juice. Mix to combine.
Fill squash halves with lamb mixture. Return to oven for 10-15 minutes or until squash is tender. Top with parsley leaves and crispy fried onions.