- Wash all the vegetables well. Break lettuce and spinach into large pieces. Cut the bell pepper in half, remove seeds and slice thinly. Slice the cucumber, celery, onions and avocado.
- Put lemon juice, salt, pepper, sugar, mustard, and garlic and olive oil in a screw top jar and shake well, until the dressing is emulsified.
- Combine all the salad ingredients in a large wooden bowl. Add dressing and toss well until they are coated with the dressing.