Step 1

Remove and discard label from can, then using a can opener, make 2 small holes in the top. Place in a saucepan, open-side up. Fill pan with cold water to come almost to the top of the can (about 1cm from top). Bring to the boil, then reduce to medium-low and simmer for 3 hours until a caramel forms, topping up water to keep the same level. Carefully remove cans and cool. Scoop out caramel, then set aside.

Step 2

Lightly grease an 11cm x 33cm loose-bottomed tart pan. Roll pastry between 2 sheets of baking paper to 5mm thick, then use to line pan. Chill for 20 minutes.

Step 3

Preheat oven to 180°C. Line the pastry with baking paper and pastry weights or uncooked rice. Blind-bake for 10 minutes, then remove paper and weights and bake for 5 minutes or until pastry is dry.

Step 4

Reduce oven to 150°C. Place chocolate in a heatproof bowl over a pan of gently simmering water, not letting bowl touch water. Allow to melt, then stir until smooth. Remove from heat and cool. Gently whisk eggs in a separate bowl to just combine (don't allow to froth).

Step 5

Heat cream and milk in a saucepan over medium heat until just below boiling point, then pour over eggs, stirring. Return to pan over low heat and stir for about 5 minutes until thick. Pour through a sieve over bowl of chocolate, stirring gently until smooth.

Step 6

Spread three-quarters of the caramel over pastry. Pour over chocolate, then bake for 5 minutes or until just set. Leave tart in switched-off oven for 1 hour with the door closed. Remove and cool completely before slicing. If desired, stir remaining caramel through some whipped cream to serve.