In a large saucepan with a tight fitting lid, add the ghee and sauté the onions over medium-high heat until softened, about 3 minutes. Add the garlic, salt and pepper and cook for 3 additional minutes.
Add the diced tomatoes and cook for 2 minutes.
Add the canned tomatoes, the broth and the dried oregano and bring to a boil, stirring a few times. Bring the heat down so the soup is at a gentle simmer, cover the pot with a lid and cook for 20 minutes.
While the soup is cooking, in a small skillet crumble the sausage and sauté for 6 minutes, or until browned and cooked through. Set aside.
Uncover the soup and add the fresh basil. Using an immersion blender, puree the soup until smooth. Skip to step 6, if you don’t have an immersion blender, let soup cool slightly, then add to a blender in batches and blend until smooth. Return the soup to the pot.
Add the brown rice and simmer, covered, for another 30-35 minutes. Remove lid and let cool slightly.
Serve soup in bowls with crumbled sausage, a drizzle of olive oil and fresh basil.