Italian sausage tomato orzo soup

Ingredients:

• 1 lb Italian sausage, casings removed
• 1 onion, diced
• 2 cloves garlic, minced
• 1 can (14 oz) diced tomatoes
• 4 cups chicken or vegetable broth
• 1 cup uncooked orzo pasta
• 2 cups spinach, chopped
• 1 teaspoon dried basil
• 1 teaspoon dried oregano
• Salt and pepper to taste
• Grated Parmesan cheese (optional, for serving)
• Fresh basil leaves (optional, for garnish)