Preheat the oven to 400°F (200°C).

Blind bake your tart shell: roll out the pie crust and line a 9-inch (23cm) tart pan with it.

Prick all over with a fork, line with parchment and pie weights, and bake for 15 minutes.

Remove the parchment and the weights and continue baking for about another 10 minutes, or until fully baked and golden.

While the crust is baking, make your filling: combine sugar and water in a saucepan and heat, without stirring, until the liquid turns a deep amber color.

Turn off the heat and while whisking carefully pour in the cream, then the butter and honey. It will bubble up a lot.

Turn the heat back on low and simmer for a few minutes, until everything is dissolved and combined. Stir in the salt and walnuts.

Pour filling into the baked tart shell and bake for 15 minutes.

Let cool completely for at least 2 hours to let the filling set before serving. Store, loosely covered, at room temperature for up to 2 days.