To a large pot, add mirepoix, garlic, broth and Parmesan rind (if using) over high heat.
When it reaches a boil, lower the heat to medium low and simmer until the vegetables become tender, about 20 minutes.
Discard Parmesan rind. Remove soup from heat.
Carefully blend the broth with the vegetables using an immersion blender in the pot, or by pouring the contents into a stand blender and blending until smooth.
Pour contents back into pot.
Return pot to medium-high heat and bring to a boil.
Add tortellini to the pot and cook for two minutes.
Remove pot from heat, then season with salt.
Divide among bowls. Sprinkle with cheese, garnish with chopped parsley, and drizzle with olive oil to serve.
