Turn on burner to med-high to heat. Rinse and drain lentils, set aside. Melt oil in pressure cooker, then add 1 tablespoon water, shallot, ginger and garlic. Cook, stirring often until fragrant; about 2 minutes. Add curry powder, brown sugar, salt, turmeric and cayenne. Stir to combine. Add lentils, coconut milk and 1 cup water. Stir to incorporate.
Seal the pressure cooker, set to high for 15 minutes (set the timer AFTER the pressure builds). After 15 minutes, naturally release for 10 minutes then vent completely. Open the lid and stir in the lemon juice.
As lentils cook, cut the squash in half. To cut cooking time, place in glass dish and add some water in the bottom. Cover and microwave in full for 5 minutes. Remove from microwave. Line baking sheet with foil. Set oven or toaster oven to 425. Prick flesh, brush with melted butter and sprinkle with brown sugar. Bake for 20 min.
Scoop lentil curry into delicata halves and serve. Keeps in fridge up to 5 days. If curry is too thick when reheating after storing, add some water to loosen.