Bring a large pot of heavily salted water to boil. Meanwhile, fill a large bowl with ice cubes and water, set aside. Once water is boiling, add asparagus and cook for 4-6 minutes, until asparagus has softened but still maintains its bright green color. Transfer asparagus directly to ice bath to stop cooking.
Cook shrimp:
Melt butter in a medium saucepan over medium heat. Stir in shrimp, add a pinch of salt and pepper, and cook until shrimp is just barely pink. Remove from heat.
Make dressing and assemble:
In a small bowl, whisk together olive oil, vinegar, shallot, and mustard. Alternatively, you can use a small jar with a lid and shake it until the dressing emulsifies.
Place asparagus on a serving platter and top with shrimp. Pour vinaigrette on top and serve immediately.
Recipe by Things I Made Today at https://www.thingsimadetoday.com/2015/06/29/shrimp-and-asparagus-in-a-sherry-vinaigrette/