Cook thin spaghetti according to package directions.
Meanwhile, heat olive oil in a large skillet over medium heat. Add asparagus pieces and cook for 4-5 minutes. Add minced garlic and cook for another minute. Add diced tomatoes, garlic salt and black pepper. Cook for another minute. Remove from heat.
Toss thin spaghetti with the cooked sliced sausage, asparagus, tomatoes and parmesan cheese. Serve immediately.