What you'll need:
3 large sweet potatoes, 1 1/2 inch chunks
1 onion, sliced very thin
3 cloves of garlic, minced
1/4 cup grade A maple syrup
1/4 cup brown sugar
3 tbsp unsalted butter
Extra virgin olive oil, as needed
Preheat the oven to 400 degrees.
Peel and cut the sweet potatoes into 1 1/2 inch chunks. Toss in olive oil and salt, spread out on a sheet tray and roast in the oven for about 45 minutes, until tender.
While the potatoes are roasting, cook the onion in a pan over medium heat with 1 tbsp of olive oil and a sprinkle of salt until it is caramelized. When it's brown, add the syrup and garlic. Cook for a few minutes more.
When the potatoes are ready and still hot, put in a large bowl with the onion, garlic and maple syrup. Mash all together and add the butter and brown sugar. You can puree everything in a food processor for a smoother consistency.
Taste for seasoning and add more salt if needed.
Scoop out into an 8x8 baking dish and bake at 350 degrees for 15-20 minutes.