Wash and dry broccoli. Chop florets into small bite-sized pieces.
Finely dice red onion.
In large bowl, combine broccoli, onion, cranberries, sunflower seeds, cheese, and almonds.
In small bowl, whisk mayonnaise, vinegar, sugar, salt, and pepper until smooth.
Pour dressing over broccoli mixture.
Toss until all broccoli is coated.
Cover with plastic wrap or transfer to airtight container.
Refrigerate at least 1 hour.
Stir before serving.
Serve cold.