Heat 2 tablespoons olive oil in a large pot over medium heat. Add the carrot, celery and onion; cook, stirring occasionally, until just golden, about 5 minutes. Add the remaining 1 tablespoon olive oil, the portobellos and herbs; cook, stirring, until the mushrooms release their juices, about 4 minutes. Increase the heat to high; cook until the mushrooms brown, 2 to 3 minutes.
Add the wine and cook to reduce, about 1 minute. Add the porcini, peppercorns, 1 1/2 teaspoons salt and 12 cups water. Bring to a simmer over medium heat and cook until reduced by about one-third, 25 to 30 minutes.
Meanwhile, cook the tortelloni as the label directs. Drain; skewer on toothpicks.
Strain the broth through a fine-mesh sieve, pressing on the solids. Skim any excess fat from the surface. Season with salt. Serve with the tortelloni and sprinkle with parmesan.