Start by gathering and preparing your ingredients. Scrape the vanilla bean to extract the seeds and zest the lemon if you're using it. Make sure everything is measured out and ready.

In a medium saucepan, combine the heavy cream and whole milk. Heat over medium-low until small bubbles form around the edges. You don't want to boil; just warm it up to infuse the flavors.

In a bowl, whisk the egg yolks with the honey and salt until smooth and well combined.

Now we're going to add our warm cream mixture to the egg mixture gradually. Do this slowly. Start by adding a small amount of the hot cream to the bowl while whisking continuously. This is crucial to avoid scrambling the eggs. Once incorporated, you can add the rest of the cream mixture in a steady stream.

Next, stir in the vanilla seeds (or paste/extract). If you're using lemon zest, mix that in as well. This is where the aromatic flavors come together.

To achieve that silky smooth texture, strain the mixture through a fine mesh sieve into a pouring jug or another bowl. This will catch any lumps.

Evenly distribute the custard mixture into small ramekins or pots. They should be filled about three-quarters full to allow for some expansion.

Place the pots in a baking dish and fill the dish with hot water until it reaches halfway up the sides of the pots. This water bath helps the custards cook evenly. Bake in a preheated oven at 325°F (160°C) for about 30-35 minutes, or until they are just set.

Once baked, remove the pots from the water bath and let them cool at room temperature. After they've cooled, cover them and chill in the refrigerator for at least two hours before serving. This allows flavors to meld beautifully.