Bring saucepan of water to a boil over high heat. Add pasta, stirring well, and cook for 5 to 7 minutes, or until al dente. Remove from heat and drain, rinsing pasta under cold water.
Meanwhile, heat 2 tablespoons oil in large skillet over medium heat. When hot, sauté garlic and portobello mushroom slices for 2 to 3 minutes. Turn slices over and continue cooking until softened. Add more oil, as needed.
Slice trimmed greens crosswise into 1-inch-wide pieces. Add half bunch to skillet. When it cooks down, add remaining greens and balsamic vinegar, stirring often.
Add pasta, crumbled gorgonzola and artichoke hearts, and continue stirring until cheese melts. Remove from heat, season with crushed red pepper to taste, if desired, and serve.