In a medium-sized mixing bowl, use a fork to combine the flour, sugar, and sea salt. Grate in the butter, and then rub into flour mixture with fingertips. Fold in just enough water so mixture holds together. Turn out onto a lightly floured surface, gather into a disc, and wrap tightly with plastic. Set in the fridge and chill for 30 minutes or longer.

Preheat oven to 375 degrees F. Liberally butter the bottom and sides of a 9-inch tart pan. 

On a lightly floured surface, roll out chilled dough into a 14-inch circle. Fold into quarters, transfer to the prepared tart pan, and unfold. Press into place, cut off all but a 2-inch overhang; fold overhanging dough into the sides of the tart, pressing to incorporate. Poke crust all over with the tines of a fork. Set crust on a rimmed baking sheet. To blind bake, line crust with foil and add pie weights, dried beans, or rice.

Bake crust with weights for 12 minutes. Carefully remove pie weights and foil lining, and then bake for another 5 - 7 minutes, until shell is a light golden brown. remove tart from oven and turn heat up to 400 degrees.

Meanwhile, make the brown butter. Add a pinch of sea salt.

Spoon jam into the bottom of the tart. Starting with the outer edge, arrange fruit slices on a diagonal, pit side facing the center, so that the fruit overhangs the edge by an inch or so. Continue tucking and arranging fruit, working your way toward the center. Brush fruit with brown butter, then sprinkle with sugar.

Set pan back on the rimmed baking sheet. Bake for 30 minutes. Rotate tart pan, turn heat down to 350, and bake for another 15 minutes, or until the edges of the fruit have just browned and the filling is bubbling.