Put the salt, pepper, mustard, orange zest and oil in a large enough bowl and mix the ingredients well. 2.
Add orange juice and sesame seeds and stir until the sauce becomes a little thick. Cover with plastic wrap and refrigerate.
Just before serving, stir in tarragon and thyme.
Mix with bitter lettuce, such as radicchio, watercress, endive and sorrel.
Variations: Replace orange zest and juice with lemon, lime, or grapefruit – zest and juice, respectively.