Preheat oven to 425°F.
For the Balsamic 'Ketchup': On a medium sized sheet tray, combine tomatoes, olive oil, salt and pepper. Toss with your hands to coat evenly. Roast in the oven for 10-12 minutes or until brown and slumped. As soon as you take the tray out of the oven, pour the balsamic vinegar over the hot tomatoes. Using a potato masher, mash the tomatoes until smashed. Reserve.
Arrange squash rounds on a large sheet tray, dress with olive oil, salt and pepper. Roast until crispy and brown, about 18-20 minutes.
Lower oven temperature to 400°F.
Over medium-high heat, heat oil in a medium skillet. Add in the onion, carrot, celery and garlic. Cook over medium heat until sautéed and lightly browned, about 10-12 minutes. Remove from heat and allow to cool.
In a mixing bowl, combine the beef, pork, turkey, egg, cauliflower rice, hazelnuts, parsley, cooled veggie mixture, salt and pepper. Using your hands, mix well to combine, but be careful not to overmix. Using a medium-size scoop or your hands, form meatballs about the size of golf balls. Place the meatballs on a medium-size sheet tray and roast for 18-20 minutes or until golden brown.
Serve with Balsamic 'ketchup' and roasted squash.
Makes about 20-22 meatballs
* To make your own riced cauliflower, trim one head of cauliflower into florets. In a food processor, process the florets into the consistency of white rice. Heat 1 tablespoon of extra-virgin olive oil a in large skillet. Add cauliflower “rice” and saute for 2-3 minutes or until tender. One head of cauliflower yields about 3 to 4 cups of 'rice.'