Measurements are approximate, will update later.
Slice the squash in half and scoop out seeds. Put a thin layer of water in a large baking dish and place squash cut side down in dish. Bake at 350°C for 30-40 minutes until tender.
Rinse the barley, rice and lentils, and put in rice cooker with bulgur wheat, spices and water. Turn on rice cooker. When most of the liquid is absorbed, open cooker and put in currants, then allow rice cooker to finish cooking.
Sauté the onions and celery in oil until slightly browned. Add apples and cook until soft.
Combine grains and vegetables, and mix in brown sugar to taste (more with granny smiths, less with sweeter apples). Scoop generous portions into the squash halves, then return to oven and bake until heated through.