Roast cashews in oven for 5-10 minutes at 350 degrees (no preheating
necessary). Cut squash in half, clean, and remove seeds.
Cut bread into small chunks. Roast in oven until brown and crisp. Set
aside.
Soak tvp in 1/2 cup hot water to rehydrate. In a skillet, melt
margarine. Add onion, mushrooms (if using), seitan, celery, carrot and
garlic. Saute for 5 minutes. Add bread, tvp, apple juice, spices,
cashews, sweetener, and 1/2 cup water. Keep stirring and adding more
water as it gets absorbed. When the stuffing is fairly moist without
being soggy, add the apples. Cook for 3-5 more minutes, then remove
from heat.
Pack squash with stuffing. Cook in 350 degree oven for 30-40 minutes, until a fork easily pierces the skin and flesh, with only a slight resistance (watch out for overcooking - delicata cookes very very quickly).