Preheat the oven to 400°F. Cut each acorn squash in half and place flesh side up on a baking sheet. Season the squash with salt and pepper and then drizzle with olive oil.
Roast the squash for 45 minutes, then remove the squash from the oven. Use a fork to see if the flesh is tender and starting to caramelize. If the squash is still tough, put back into the oven for another 10 minutes.
Add 1 tablespoon of butter and 1 tablespoon of brown sugar to each squash half. Divide the chopped nuts between the squash (you might have some extra that you can use for garnish) and then place in the oven for 7-8 minutes.
Garnish with chopped chives and serve.
Serves 8 people.
To Reheat: Leave the foil on to trap moisture and roast in the oven at 400°F until just warmed through.
To Freeze: Freeze fresh cubed acorn squash or mashed roasted acorn squash up to 3 months.