Prepare Classic Sweet Pastry. Wrap and refrigerate it for at least 1 hour.
At least 15 minutes before baking, position rack in lower third of oven; preheat oven to 375 degrees.
Rolling the Dough
Roll the dough into an 11- to 11½-inch circle ⅛ inch thick as directed. Fit the dough into the pan; trim the overhang by rolling the pin across its rim.
Bake in preheated oven for 10 to 12 minutes, or until the surface of dough no longer looks raw or shiny but appears set and ivory-colored. (Check after 5 to 6 minutes in the oven for signs of the crust’s blistering; if necessary, prick it in 4 to 5 places to release steam so that the dough fits the pan snugly.)
Remove from the oven to a cooling rack while you prepare the filling.
Making the Filling
Place eggs in a small bowl and whisk just to combine. Pour in the sugar and whisk. Add the lemon juice, again whisking to combine. Add the cooled melted butter and lemon zest and blend.
Baking the Tart
Pour the filling into the partially baked pastry shell.
Return to 375-degree oven and bake for 16 to 18 minutes longer, or until the crust is golden and the filling is set. (The filling bubbles toward the end of baking.) Remove and cool on a rack for 10 minutes.
Set the pan on a narrower elevated surface (such as a tin can), so the bottom of the pan is released as the metal rim slips down. Cool to room temperature.
Preparing the Fruit
Heat the apricot jam just until melted but not bubbly hot. Pour into a 2-quart mixing bowl. Pour the blueberries next to the warm preserves and toss gently with a rubber spatula briefly to coat most of them. Spread over the tart, leaving a 3-inch center portion of lemon filling uncovered. Serve the same day for best flavor.