Heat a large grill pan over medium-high heat.
While pan heats, bring water to a boil in a large saucepan.
Add steak to grill pan; grill 5 minutes on each side or until desired degree of doneness. Sprinkle steak with salt. Cut steak across grain into thin slices.
While steak cooks, add asparagus to boiling water; cook 2 minutes. Remove asparagus with a slotted spoon. Add noodles to boiling water; cook 3 minutes or until done. Drain; rinse well. Cut noodles into smaller pieces; place in a medium bowl.
While noodles cook, combine sugar, lime juice, fish sauce, and curry paste in a large bowl. Add one-half of lime mixture to medium bowl with noodles; toss to coat. Add steak, asparagus, tomatoes, and basil to remaining lime mixture in large bowl; toss to combine. Serve steak mixture over noodles.