Make the Tart Dough: combine flour salt and pepper in a food processor and pulse just to combine. Add the butter and pulse until the mixture resembles wet sand - about 10 pulses, butter pieces should be +/- pea size. With mixer running, pour in water and stop as soon as the dough begins to form a ball. Shape into a disc, wrap in plastic and refrigerate for 30 minutes.
Preheat oven to 350˚F and have your 10in tart pan with removable bottom ready. Roll out dough to 10-11 inches and about ¼ inch thick - to get a nice circle roll out from the center forward and back, rotate the dough a ¼ turn (dusting with flour when needed) and repeat - make sure not to roll off the edge of the dough, this will make a very thin and breakable edge.
To move dough into tart pan, make sure it is well floured then gently roll it onto your rolling pin and then roll it back out on top of the tart pan. Gently press dough into the pan, roll your rolling pin across the top to cut off excess dough and prick bottom with a fork.
Line dough with parchment, fill with dried beans and blind bake for 20 minutes. Remove the beans and parchment and bake another 20 minutes until crust is golden brown. Let cool completely.
Pipe or spread the mascarpone filling into cooled tart shell and top with as many strawberries as you possibly can. Give a quick grind of pepper over top the tarts (mostly for the look) and serve immediately.