Preheat oven to 375 F . Line large baking sheet with parchment and set aside.
In large bowl, combine tomatoes, diced sweet potato, red pepper, and garlic. Drizzle with half the olive oil and toss to lightly coat. Spread out on baking sheet in an even layer. Roast in center of oven for 35 to 40 minutes, or until vegetables are lightly charred.
In large heavy saucepan over medium heat, add remaining oil, diced onion, carrot, and celery. Sauté, stirring often until onions are soft and clear and carrots and celery are just turning slightly golden, about 15 minutes. Add a splash of water, if necessary, to keep vegetables from sticking. Add sun-dried tomatoes and harissa and stir in. Then add vegetable stock and bring to a gentle boil. Remove from heat and set aside while vegetables in oven finish roasting.
When oven-roasted vegetables are done as you like, transfer along with any of their precious juices to saucepan with vegetable stock mixture. Stir in, return to heat, and bring to a gentle boil to fully amalgamate flavors. Stir in vinegar and maple syrup. Using handheld stick blender or high-speed blender, purée mixture until smooth and creamy. Add a splash more vinegar coupled with salt and pepper, to taste, if you wish.
Serve steaming hot in mugs or bowls with your choice of toppings. Soup can be refrigerated for up to 4 days or frozen for longer storage.
Recipe Notes
Per 1 cup serving: 119 calories; 3 g protein; 4 g fat (1 g sat. fat); 19 g total carbohydrates (10 g sugar, 4 g fiber); 214 mg sodium