In a salad bowl mix mayo, salt, pepper, mustard (if using), and any other seasonings you like (I sometimes use potato seasoning). Add chopped herbs. I prefer dill, but basil or parsley worked just fine.
Separate the cauliflower into small florets using fingers or knife. Add to the bowl.
If using regular tomatoes, chop them and add to the bowl and mix in. If cherry tomatoes - halve them and put on top of salad in a bowl or a plate. Serve.