Preheat the oven to 350°F (180°C). Clean and slice the white parts of the leeks into rounds. Heat the water and dissolve the bouillon cube in it. Add the leeks and simmer gently for 5 minutes. Add the polenta and keep stirring. Cook for 1 minute. Remove from heat and set aside.

In a bowl, beat the eggs with the ricotta. Season with salt and pepper, then pour into the pot with the polenta and leeks. Mix well. Add the smoked salmon, cut into small pieces, and the shredded cheese.

Pour the mixture into a silicone baking pan or a pan lined with parchment paper. Bake for 40 minutes. Let cool completely before removing from the pan.