Pastry:

• 1 1/4 cups unbleached all-purpose flour (organic preferred), dipped and leveled
• 3 tablespoons sugar
• 1/4 teaspoon salt
• 1/2 cup (1 stick) chilled unsalted butter, cut into pieces, plus more for buttering pan
• 1 1/2 large egg yolks blended with 1 1/2 tablespoons ice water

Filling:

• 1/2 cup (1 stick) unsalted butter
• 1/2 cup packed dark brown sugar
• 1/4 cup honey
• 2 tablespoons granulated sugar
• 1 cup toasted, salted cashews (about 4 ounces)
• 2/3 cup toasted, salted macadamia nuts (about 3 1/2 ounces)
• 1/2 cup whole, blanched almonds (about 2 1/4 ounces)
• 1/3 cup salted, shelled pistachios (about 1 1/2 ounces)
• 1/4 cup pine nuts (about 1 ounce)
• 2 tablespoons heavy cream
• 1 1/2 teaspoons coarse salt

1. Make the pastry: Place the flour, sugar, and salt in the bowl of a food processor and pulse a few times to combine. Add the butter and pulse until the mixture resembles coarse meal. Add the egg yolk mixture and pulse until a dough begins to form. Gather the dough into a ball, flatten into a disc, wrap in plastic and refrigerate at least 30 minutes.

2. Butter an 11-inch-diameter false-bottom tart pan. Let the dough soften slightly, then pat the crust into the pan with your hands until it is to a relatively even thickness of 1/8 inch. Trim the edges even with the pan’s rim. Refrigerate the pastry for 30 minutes to overnight.

3. Prebake the tart shell: Preheat the oven to 400°F. Line the tart shell with foil. Fill with dried beans or pie weights. Bake for 10 minutes. Remove the foil and beans. Bake for 10 minutes longer, or until the tart shell is golden brown. Cool completely on a rack.

4. Make the filling: Reduce the oven temperature to 350°F. Place the tart shell on a heavy, large baking sheet. In a heavy 2-quart saucepan, combine the butter, brown sugar, honey, and granulated sugar. Cook over low heat, stirring until the sugars dissolve. Increase the heat and whisk until mixture comes to a boil.

5. Continue boiling until large bubbles form, about 1 minute. Remove the pan from the heat. Stir in the cashews, macadamia nuts, almonds, pistachios, pine nuts, and cream. Immediately pour the filling into the tart shell. Bake about 20 minutes, or until the filling bubbles (the filling might overflow slightly onto baking sheet).

6. Cool the tart in pan on a rack until the filling just begins to set. Gently remove the pan bottom and cool the tart completely, 4 to 5 hours. Sprinkle with salt to taste. Cut into wedges and serve.