In the bowl of a food processor, combine the sugar, lemon zest and rosemary. Pulse for at least one minute to distribute the oils in the zest and herbs throughout the sugar.

Add the flour and pulse again. With the processor running, add in the butter a few cubes at a time, then add the egg yolks and the ice water. Let the processor run until all the dough is gathered into a single ball.

Turn off the food processor as soon as this happens to avoid over-mixing. Wrap the dough in waxed paper, and let it rest for 30 minutes.

Preheat the oven to 400°F.

On a lightly floured surface, roll the dough to ⅛-inch thickness. Using your rolling pin, loosely roll up the dough, then unroll into an 11-inch tart pan. Press in the bottom edges, then roll your rolling pin over the edges to trim the excess. Place your tart crust in the freezer for 30 minutes before docking with a fork or toothpick, and baking for 18–20 minutes until golden brown. Reduce the oven temperature to 350°F.

In your food processor, pulse together the brown sugar, salt and rosemary leaves for at least 1 minute.

In a saucepan over low heat, combine the rosemary sugar and honey, and cook until the sugar has dissolved, stirring only occasionally. Bring the mixture to a boil, and boil for 1 minute without stirring.

Remove from the heat, stir in the cream, and then the nuts. Pour immediately into the tart crust, spreading it evenly throughout.

Bake for 20 minutes, until the filling starts to bubble around the edges. Let cool and set before cutting to serve.