Toast a cup of almonds in a shallow pan over medium heat for 5-6 minutes, until fragrant. Remove from heat and reserve.
Combine raisins with sherry vinegar in a small sauce pan, bring to a boil, remove from heat and allow to steep for 10-15 minutes
Combine mayo, milk, sugar, vinegar, pinch of salt and black pepper in a large bowl, stir to combine. Finely chop 1 stalk of celery and slice red seedless grapes in half and add to dressing
Drain raisins from vinegar and add to dressing.
Add roasted broccoli and red onion to dressing and toss all to combine.
Sprinkle with toasted almonds and gently toss to combine.