Grind the walnuts with a spice grinder to yield about ½ cup. Whisk flour, powdered sugar, salt and ground walnuts in a large bowl; with hands, work in butter and cheese until it resembles coarse crumbs. Whisk egg in a bowl; stir into flour mixture with a wooden spoon until the dough comes together.
On a floured surface, form the dough into a 1-inch-thick disk; wrap tightly in plastic wrap and refrigerate for 2 hours.
On a floured surface, roll the dough into a 12-inch circle; transfer to a 10-inch tart pan, about 1-inch deep, with a removable bottom. Press the dough firmly into bottom and sides of the pan; trim off any excess dough. Line the dough with foil and fill with pie weights or dried beans; place on a half sheet tray. Bake at 425°F for 10 minutes; remove pie weights and foil. Bake 5 minutes; let cool.
For the poached apples:
Whisk wine, honey, rosemary, peppercorns, and nutmeg in a large saucepan; heat to a boil while stirring with a whisk. Reduce heat to low and simmer 5 minutes. Add the apples; press a circle of parchment paper over the apples. Cover the saucepan; poach the apples for 50 minutes, turning apples halfway through. Remove apples from poaching liquid to cool and thinly slice; reserve poaching liquid in saucepan.
For the honey-brown butter drizzle:
Heat reserved poaching liquid to a boil over high heat; reduce heat to medium and cook 30 minutes or until reduced to a thick consistency.
Cook butter in saucepan over medium-low heat 8 minutes or until it turns a golden amber color, stirring frequently. Stir in honey and ½ cup reduced poaching liquid; cook 7 minutes, stirring frequently. Remove from heat; whisk in cream, salt and pepper until smooth. Let cool to room temperature; cover and refrigerate. Makes about 1¼ cups.
For the glaze:
Add water to the remaining reduced poaching liquid and stir until smooth.
For the cheese filling:
Melt butter in a large saucepan over medium heat; stir in flour and cook for 3 minutes, stirring constantly. Whisk in cream, rosemary, salt, pepper and nutmeg; cook 5 minutes or until the mixture starts to thicken, whisking constantly. Remove from heat.
Whisk eggs in a bowl. To temper eggs, transfer ½ cup of the warm cream mixture into the eggs while whisking constantly; whisk cream-egg mixture back into warm cream mixture in saucepan. Whisk in cheese, then whisk in cream cheese until smooth; if necessary, use an immersion blender to achieve a smooth consistency.
To assemble the tart:
Pour the cheese filling into the crust; sprinkle with ½ cup walnuts. Arrange sliced, poached apples over filling in a circle, starting with the outside and working inward, overlapping the layers of apple. Gently brush the top with some of the glaze.
Bake tart on half sheet tray at 325°F for 50 minutes; gently brush the top with some of the glaze and sprinkle with remaining 2 tablespoons walnuts. Cool tart 45 minutes; refrigerate at least 1 hour before cutting into wedges.
Place wedge of tart on dessert plate; drizzle with a generous amount of the honey-brown butter drizzle.