public void Rollback()
{
    dbContext.Dispose();
    dbContext = contextFactory.CreateDbContext();
}

public class StepViewModel
    {
        [Key]
        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public int Id { get; set; }
        [Required]
        [StringLength(100)]
        public string Name { get; set; }
        [Column(TypeName = "ntext")]
        public string Goal { get; set; }
        [Column(TypeName = "ntext")]
        public string Description { get; set; }
        public int StageId { get; set; }
        public StageViewModel Stage { get; set; }
        public IEnumerable<StageViewModel> StageDropDownListItems { get; set; } // здесь отличие от  db и dto классов
    }

        [HttpGet]
        public ActionResult Create()
        {
            var stages = stageService.GetStages(); 
            var stagesVM = mapper.Map<IEnumerable<StageViewModel>>(stages);
            var model = new StepViewModel()
            {
                StageDropDownListItems = stagesVM
            };
            return View(model);
        }