Step by step

Add the opened (cooked) clams with their shells removed and a little cooking water

Tips
You can keep lasagna in the fridge in an airtight container for 2-3 days at most.
Trivia
Although lasagna has known its greatest fame and has spread across the world since World War II onwards, in ancient Rome there was a similar dish. And we read in ‘The culinary art of Apicius’ that lasagna was the favourite dish of Cicero.