Shred the cabbage and soak in cold water for 5 minutes, then drain it.
Cut the cherry tomatoes in half.
Boil the chicken breast and shred it into bite-sized pieces.
Slice the avocado thinly.
Mix olive oil, lemon juice, salt, and pepper to make the dressing.
Put all the ingredients in a bowl, pour the dressing over, and toss to combine.