1. Preheat broiler with oven rack 5 1/2 inches from heat. Broil peppers and corn at the same time on an aluminum foil-lined jelly-roll pan. Broil peppers 10 minutes or until blistered, turning after 5 minutes. Broil corn 20 minutes or until charred, turning every 5 minutes. Place peppers in a zip-top plastic freezer bag; seal and let stand 10 minutes to loosen skins. Peel peppers; remove and discard seeds. Chop peppers. Cut corn kernels from cobs. Reduce oven temperature to 400°.
2. Cook pasta in boiling salted water to cover 8 to 10 minutes or until al dente. Drain.
3. Cook chorizo in a medium skillet over medium heat, stirring often, 2 to 3 minutes or until crisp; remove chorizo, and drain on paper towels. Discard drippings.
4. Melt 3 Tbsp. butter in a large heavy saucepan over medium heat; whisk in flour until smooth, and cook, whisking constantly, 2 minutes or until golden brown. Slowly whisk in milk, and cook, whisking often, 10 to 12 minutes or until thickened. Remove from heat, and gradually add cheese, stirring until smooth. Stir in chopped peppers, corn kernels, chorizo, salt, and pepper. Gently stir together cheese mixture and pasta in a large bowl. Spoon into 6 (8-oz.) ramekins.
5. Combine tortilla chips, panko, and 3 Tbsp. melted butter; sprinkle over pasta.
6. Bake at 400° for 12 to 15 minutes or until golden and bubbly. Let stand 5 minutes before serving.