Roll out one portion of pâte brisée and line a 10 inch tart pan. Dock the bottom of the pastry with a fork.
Mix all of the ingredients (except the reserved whole pecans) in a large bowl with a whisk. Pour into the lines tart pan. The filling should should stop about 1/4” from the tip of the pan. Arrange the pecans halves in concentric circles, beginning with the outer ring and work towards the center.
Bake on a sheet tray for 45-50 minutes. You may need to place a sheet of aluminum foil over the tart for the last 20 minutes if the pecans are getting too dark. The filling will puff up and have a slight giggle in the center, but it will settle and firm up as it cools.
Allow the tart to cool before removing from the tart pan. Serve it at room temperature or slightly warm.