In a cast iron pan on low heat, I melted one tablespoon of butter along with one tablespoon of olive oil. I added the garlic, a dusting of crushed red pepper flakes and a small sprinkle of dried thyme (no more than 1/4 teaspoon, I'd estimate). If you have fresh rosemary, a sprig would be great here also.
I let that swirl around for about thirty seconds - you don't want the garlic to brown or burn - and then added the onions. Season generously with salt, black pepper, and one teaspoon brown sugar.
Let that caramelize - don't stir too often or you won't get that lovely brown color, and don't try to speed things up by raising the heat. Low and slow is what you want.
This took about thirty-five minutes or so. Half way through I added a shot of brandy - the alcohol and sweetness helping to heighten the caramelization.
When roasting any hearty squash, I like to pop it into the microwave for a few minutes (this one is a smaller squash, so 2-3 minutes should do the trick) just to soften it up a little before cutting it in half.
After I took the squash out of the microwave and let it cool, I cut it in half and scooped out the seeds and guts. (Save the seeds to roast if that's your thing, obvi).
Then I rubbed both halves with olive oil and sprinkled generously with sea salt, black pepper, and a dash of garlic powder.
Place both halves on a baking sheet and roast at 350 degrees until soft and cooked through, about 35 to 40 minutes.
The squash is so hearty, and the onions so flavorful, this is perfect as a vegetarian entree.
To serve more than two people, just cut the squash into wedges or slices rather than halves, and drape the onions on top.