Core and seed approximately a dozen large tomatoes.  Toss them in a food processor and puree, working in batches.  In a large stock pot on medium high heat, cook the garlic in the olive oil until fragrant and then add the pureed tomatoes.  Bring to a boil, season with salt, pepper, and sugar, then turn down to a simmer untill all the water is cooked out, about 2 to 3 hours.  Stir the sauce every ten minutes or so to prevent burning.

Preheat the oven to 350.  Spatchcock the chicken along the back, massage with olive oil, and season with salt and pepper.  Bake until the skin is browned and crispy, about an hour.

While the chicken is roasting, slice a medium sized sweet onion into wedges thick or thin depending on how you like to eat them.  Cook them in a saute pan over medium high heat with the butter, stirring every few minutes to prevent burning.  When the bottom of the saute pan begins to get a brown film, add the wine and cook until the liquid is reduced by a third, about 15 minutes give or take.  Add the onion mixture to the tomato sauce.

When the chicken is done, cut into serveable pieces using poultry shears (I cut the breasts in half) and serve on top of the tomato sauce.