Toast the pistachios in a non-stick frying pan without any oil. Remove and set aside. Mix the bread with the oil, garlic and salt, fry with the onion in the same pan for approx 5 mins. until crispy, turning occasionally.
Combine the mustard, lemon zest, lemon juice and oil in a bowl, season. Add the cherries, celery and olives with the bread mixture, mix together. Mix in the basil.
Plate up the bread salad, tear the burrata and place on top, season. Scatter the reserved pistachios on top.