In a large bowl, whisk together the flour, powdered sugar, and salt. Add cold butter and cut into flour until coarse crumbs form. Gradually add ice water until dough comes together.

Form dough into a disc, wrap in plastic wrap, and chill for at least 30 minutes.

Roll out dough to a 12-inch circle and transfer to a 9-inch tart pan. Press into pan, trim excess dough.

Prick crust with a fork, line with parchment paper and pie weights. Bake at 375°F (190°C) for 15 minutes. Remove paper and weights, bake 5-10 more minutes until golden brown. Cool completely.

In a saucepan, combine sugar, butter, lemon juice, and zest. Cook over medium heat, stirring until melted and sugar dissolved.

Whisk eggs and yolks in a bowl. Slowly drizzle hot lemon mixture into eggs, whisking constantly to temper. Pour egg mixture back into saucepan.

Cook over medium-low heat, stirring constantly until curd thickens to coat the back of a spoon (5-7 minutes). Do not burn.

Strain lemon curd through a sieve into a bowl. Cover with plastic wrap directly on surface. Chill for at least 2 hours.

In a heatproof bowl, combine egg whites and cream of tartar. Place over simmering water, whisk until warm and sugar is dissolved.

Remove from heat and whip with electric mixer until stiff, glossy peaks form.

Pour chilled lemon curd into cooled tart crust. Spread or pipe meringue over curd.

Use a kitchen torch to brown meringue, or broil briefly in oven (watch carefully).