1. Dice onion, mince garlic, chop basil, and cut chicken into bite-sized pieces.

2. Heat olive oil in a Dutch oven over medium-high heat and sear chicken until golden, about 5 minutes, then remove.

3. Add onion to the same pot and cook until translucent, about 3 minutes, then stir in garlic and red pepper flakes for 30 seconds.

4. Pour in tomatoes and scrape up browned bits from the pot, then add broth, oregano, and return chicken to pot. Bring to a boil, then simmer for 10 minutes.

5. Stir in orzo and cook, stirring occasionally, until al dente, about 8 to 10 minutes.

6. Remove from heat and stir in basil, lemon juice, and Parmesan. Adjust seasoning with salt and pepper.

7. Ladle into bowls, garnish with extra basil or Parmesan, and serve immediately.