Step 1

Combine half and half, 1/3 cup sugar, and salt in a heavy-bottomed saucepan. Heat until bubbles form around the edges and wisps of steam rise from the pot. Remove from heat.

Step 2

While half and half mixture is heating, whisk together egg yolks, remaining 1/3 cup sugar, and cornstarch in a bowl until a light yellow color.

Step 3

Slowly add about half of the hot half and half mixture to the egg yolk mixture, whisking constantly. ("Tempering" the eggs.) Whisk tempered eggs into the remaining half and half mixture. Cook over medium-low heat, whisking constantly, until thick and smooth. (Mixture will coat the back of a spoon.)

Step 4

Remove from heat and whisk in vanilla extract, lemon juice, and butter until smooth. Pass mixture through a mesh strainer into a bowl and discard any small egg solids. Stir in lemon zest.

Step 5

Cover pastry cream with a piece of plastic wrap pressed directly onto the surface to prevent a skin from forming. Refrigerate until well chilled.

Step 6

Spoon chilled pastry cream into tart shell and spread to an even layer. Top with strawberries, blueberries, and raspberries.

Step 7

In a small saucepan, heat jelly with water (if using), just until melted. Pass through a fine mesh sieve to remove any bits of fruit in the jelly. If using Limoncello instead of water, add it after straining.

Step 8

Lightly brush the berries with the glaze. Slice the tart into wedges and serve immediately.