Actually a custard, this dessert bakes like a tart; the filling is firm enough to cut into wedges.
Preheat oven to 275 degrees. Fill a large bowl with cold water, and squeeze the juice from the lemon quarters directly into the water; add the rinds. Slice pears 3/8 inch thick; add to acidulated water.
In a medium saucepan, bring the milk to a boil. Meanwhile, whisk sugar, eggs, egg yolks, and brandy in a large bowl until the batter leaves a ribbonlike trail on the surface for 3 seconds when you raise the whisk. Slowly add hot milk to egg mixture, whisking constantly, until milk has been incorporated.
Using a slotted spoon, lift pears from the water, and blot dry with paper towels. In a 10-inch-round pie plate, arrange pears in a circular pattern. Pour milk-and-egg mixture over pears.
Place pie plate in a shallow baking pan, and fill the pan with enough boiling water to cover the pie plate halfway up. Transfer to oven; bake until the custard has set and is just brown, about 1 1/2 hours. Transfer to a wire rack to cool slightly before serving.