1Heat oven to 425°F. In 8-inch square (2-quart) glass baking dish, toss asparagus, onions, shallot, oil, salt and pepper. Roast uncovered 15 to 20 minutes until vegetables are tender and lightly browned.
2Meanwhile, cook and drain pasta as directed on package.
3In medium saucepan, melt butter over medium heat. Stir in flour with whisk until blended. Cook about 2 minutes, stirring occasionally, until golden. Gradually stir in milk; cook and stir until thickened. Add cheese and dried basil; stir until cheese is melted. Remove from heat. Season with salt and pepper.
4Add cooked pasta to baking dish with roasted vegetables; toss. Pour cheese sauce over mixture; stir well to coat. Garnish with basil leaves. Serve immediately.