Blood orange, mozzarella & rocket salad

• 3 blood (or normal) oranges
  

  Orange

  or-ange

  One of the best-known citrus fruits, oranges aren't necessarily orange - some varieties are…

• 2 x 125g balls mozzarella, the best you can afford (or burrara, if you can get it), torn
• 2 big handfuls rocket
  

  Rocket

  roh-ket

  Rocket is a very 'English' leaf, and has been used in salads since Elizabethan times. It…

• ½ red onion, thinly sliced
• crusty bread, to serve (optional)

For the dressing

• 3 tbsp olive oil
  

  Olive oil

  ol-iv oyl

  Probably the most widely-used oil in cooking, olive oil is pressed from fresh olives. It's…

• 3 tbsp red wine vinegar
• 2 tsp caster sugar
• 2 tsp wholegrain mustard
• 1 tsp mustard seed (black or brown)
• 1 tsp poppy seed