Bring a large pot of salted water to boil over high heat. Cook the spaghetti per instructions. While the pasta cooks, heat the olive oil in a small skillet over medium heat then add the mushrooms & asparagus. Cook the mushrooms and asparagus, stirring often, until golden and tender, about 5-6 minutes. Season with sea salt and freshly cracked pepper, to taste.
Meanwhile, add water to a pan, filling it two thirds full; bring to a boil. Reduce heat to simmer. Coat a poaching cup (or custard cup) with cooking spray then place in the water. Break the egg into the cup then cover the pan with a lid and cook for 4-6 minutes or until the whites are firm but the yolk is soft.
Drain the cooked pasta then place back into the pan. Add the butter, asparagus, mushrooms, sea salt and freshly cracked pepper, to taste, then toss until mixed combined. Pour into a bowl, top with the poached egg, and Parmesan cheese. Serve immediately. Enjoy.