(pseudo ish)

const actors = [{name:'Johnny Dopp'}, {name:'Brad Pitts'}]

const actorIds = Promise.all(actors.map((actor)=>photon.artists.upsert({
    where: { name: actor.name },
    update: {},
    create: actor
  }))

photon.movie.create({
    name: "something",
    cast: {
      connect: actorIds.map(actor=>actor.id)
    }
  })

photon.movie.create({
    name: "something",
    cast: {
      upsert: [ 
          {name:'Johnny Dopp'}, 
          {name:'Brad Pitts'}
      ]
    }
  })