Buckwheat Pasta Primavera

Bring broth to simmer in heavy medium saucepan. Rinse mushrooms briefly under cold water. Add mushrooms and sun-dried tomatoes to broth; simmer until tender, about 4 minutes. Using slotted spoon, transfer mushrooms and tomatoes to plate; cool. Add carrot and sugar snap peas to broth and cook until crisp-tender, about 3 minutes.Using slotted spoon, transfer vegetables to another plate. Boil broth remaining in saucepan until reduced to 1/4 cup, about 5 minutes. Reserve broth. Discard mushroom stems. Slice mushroom caps and tomatoes. Melt butter in heavy large skillet over medium-high heat. Add onion; saut until tender and golden, about 8 minutes. Add bell pepper and garlic; stir until bell pepper is tender, about 4 minutes. Add carrot, sugar snap peas, mushrooms, sun-dried tomatoes, reserved broth and cream to skillet and bring to boil. Season with salt and pepper. Meanwhile, cook pasta in large pot of boiling salted water until tender but still firm to bite, about 4 minutes. Drain. Place pasta in large bowl. Pour vegetables and sauce over pasta. Sprinkle with 1 cup Parmesan; toss to coat. Garnish with green onions. Serve, passing additional Parmesan separately.