Bring a large pot of lightly salted water to a boil. Add pasta, and cook for 8 to 10 minutes or until al dente; drain.
Heat oil in a large skillet over medium high heat. Saute onions until golden brown, about 10 minutes. Stir in garlic, and cook for 2 minutes. Remove from heat, and stir in balsamic vinegar.
In a large bowl, combine pasta, onion mixture, and Gorgonzola. Toss until evenly coated, and cheese is melted.
