Cook tortellini as directed on package, adding peas during last 3 to 4 minutes of cooking time. Drain; cover to keep warm.
Meanwhile, melt butter in large nonstick skillet over medium-high heat. Add mushrooms and garlic; cook and stir 2 to 4 minutes or until mushrooms are tender. Add cream; bring to a boil. Remove from heat.
Add cooked tortellini and peas; stir gently to coat. If desired, sprinkle each serving with shredded fresh Parmesan cheese. If desired, garnish with fresh herbs.