French Lemon Tart (Tarte au Citron)

Step 1: Prepare and blind-bake the empty tart crust. Let it cool completely before filling so it does not go soggy.

Step 2: Preheat the oven to 180°C / 350°F (160°C fan).

Step 3: Put all the filling ingredients in a medium saucepan and whisk to combine.

Step 4: Set the saucepan over low to medium-low heat. Whisk constantly, especially as the butter melts, to prevent the mixture from splitting. Keep stirring until the filling thickens enough to mound visibly and hold its shape briefly when dolloped onto the surface. This takes about 5 minutes, though it may take longer depending on the stove and how well the saucepan retains heat. Do not remove it from the heat before it is thick enough, or the filling may not set.

Step 5: Pour the filling into a bowl through a fine-mesh strainer.

Step 6: Pour the filling into the tart shell and smooth the surface with an offset spatula or similar utensil.

Step 7: Bake for 5 minutes. The custard will still feel soft but should not be liquid; it will set further as it cools and become sliceable.

Step 8: Let the tart cool completely so it sets before slicing. Serve with crème fraîche, whipped cream, or vanilla ice cream if desired.

Step 9: If desired, decorate with lemon slices, edible flowers, or raspberries. Alternatively, pipe on whipped cream or dust with icing sugar.