Heat olive oil in a large stock pot or Dutch oven over medium to medium-low heat. Add chopped shallots and sauté for 4-5 minutes. Add chopped celery and carrots and sauté for and additional 5-6 minutes.
Meanwhile, cut tomatoes into wedges, leaving core and skin intact. Once veggies have cooked in step 1, add tomato wedges to the pot along with garlic, sugar, salt, ground black pepper, onion powder, and bay leaf. Cook uncovered for 20-25 minutes, gently stirring every 5 minutes, until tomatoes have broken down some.
Remove stock pot from heat and discard bay leaf. Place the fine grinding disc into the food mill and place over a large sturdy bowl. Place 3-4 ladlefuls of the cooked tomato mixture into the food mill and process to puree as much as possible. Scrape the underside of the food mill over the large bowl and discard contents from inside the food mill. Repeat with remaining tomato mixture until all is pureed.
Carefully return the puree to the stock pot, whisk in stock, paprika and Aleppo pepper flakes, and simmer for 15 minutes.
Ladle 2-3 cups of cooked puree into a quart-size measuring cup. Whisk rice flour into this cooked puree slowly and mix well; mixture will thicken. Carefully pour thickened puree back into the stock pot, whisking well to combine. Cook for an additional 10 minutes over very low heat. Season to taste with salt.
To serve, ladle soup into bowls and garnish with grated Romano, fresh basil, and fresh cracked pepper.