First, cut your acorn squash in half and set the oven to 375 on roast. Clean out the middle of the acorn squash and drizzle one tablespoon of grape seed oil onto a baking pan. Lay the acorn squash inside down, flesh side up. Roast for about 20-30 minutes, until the inside is nice and soft.
Once the acorn squash is in the oven, time to get the stuffing ready. Cut the onion into quarters and then slice. Cook on the stove in a skillet with the tablespoon of salted butter. Cook until they're nice and brown.
While the onions are cooking, dice the avocado and the feta cheese and place in a bowl with the mixed nuts and cranberries.
Check on the squash - you don't want it over cooked, otherwise it'll turn to mush.
Add the last tablespoon of grape seed oil and the balsamic vinegar to the stuffing mix. Let the onions cool a bit, then add them in.
Stuff your acorn squash and then eat up!