Sauté Veggies: Bring a Dutch Oven to medium-high heat. Add 2 tablespoons butter. Let melt and swirl to coat the pan. Add 1 teaspoon garlic and move around pan until fragrant, approx. 1-2 minutes. Add onion, carrots and celery. Season lightly with kosher salt and ground black pepper. Sauté for 3-5 minutes or until onion has softened. 

Combine: Add broth, crushed tomatoes, tomato paste, 1 teaspoon Italian seasoning, 1 1/4 teaspoon kosher salt, 1/4 teaspoon ground black pepper, pinch of red pepper flakes, 1 teaspoon lemon zest and 1 tablespoon coconut sugar. Stir to combine. 

Simmer: Add parmesan rind. Cover and let simmer 15-20 minutes. Taste and adjust seasoning, salt, etc.

Orzo: Meanwhile, bring a separate pot of water to a boil and cook the orzo to al dente, according to package instructions. Drain and set aside.

Serve: A few minutes before serving, add two handfuls of fresh baby spinach to the soup. Stir to combine. Add orzo to an individual bowl, ladle soup over top. Garnish with additional parmesan cheese (grated, shredded or shaved), fresh basil and some crusty sourdough bread with butter.