Start by collecting the zest of your orange and throw that into a small mixing bowl.
Add the vinegar, mustard, salt and pepper and mix well.
Over that same bowl, cut your orange into supremes, in order to collect the juice but throw the supremes into a larger, separate bowl. When you’ve got all your supremes done, make sure to squeeze all the remaining juice out of the membrane that’s left behind.
Throw the rest of the ingredients in with the orange supremes. Pour reserved "vinaigrette" and mix well.
Transfer to serving plate and garnish with a slice of orange, if desired.