In a large pot cook pasta according to package directions; drain. Return pasta to pot. Cover and set aside.
Place a steamer basket in a large saucepan. Add water to just below the bottom of the basket. Bring water to boiling. Add leeks. Cover and steam for 2 minutes. Add broccoli and carrots; cover and steam for 3 minutes or until vegetables are crisp-tender. Add pea pods. Cover and steam for 1 minute or just until crisp-tender. Add vegetables to pasta in pot. Stir in tomatoes. Cover to keep warm.
Meanwhile, for sauce, in a medium saucepan combine butter and garlic. Cook and stir over medium heat until butter is melted. Cook about 5 minutes more or until butter is lightly browned, stirring occasionally. Remove from heat. Stir in wine and thyme. Return to heat; heat through.
Add the sauce and nuts to pasta and vegetables Toss to mix. Season with salt and pepper. Top with cheese.