With  The Mandalorian and Grogu just weeks away now, Lucasfilm and Disney are mining the film’s explosive opening action sequence for all its worth—after showing it off at CinemaCon last month , and preparing to showcase it to fans at special IMAX teaser screenings for  Star Wars Day, a trimmed-down tease of the near-20-minute sequence is now streaming online for all to see. If you have a Disney+ subscription, that is. It’s the home of  The Mandalorian , after all! Titled  The Mandalorian and Grogu: A Special Look , the near-four-minute clip is viewable from the homepage of Disney+ today and offers a condensed highlights reel of the film’s opening sequence, following Din Djarin (Pedro Pascal) and his young ward Grogu as they battle Imperial Remnant forces on an ice world.…