Fill a big bowl with water. Add 2 teaspoons of salt and 1 teaspoon of cooking oil. Stir lightly. Drop the fresh clams into the water. Let them sit for 30 minutes. The salt and oil make the clams breathe harder, so they push out any sand hiding inside their shells.
After 30 minutes, rinse the clams under running water until the water is clear.
Put the clams into a pot. Add 1 cup of water and a tbsp of whisky.
Cover the pot with a lid and turn the heat to medium-high.
In about 3–5 minutes, the clams will start to pop open. Some will open faster than others.
As soon as a clam opens, take it out with tongs and set it aside. Keep cooking the rest until they all open.
If any clams stay closed after a few more minutes, throw them away. They are not safe to eat.
Check the cooked clams for any remaining sand. If you see sand, rinse each clam under running water until it's clean.
Arrange the clams in the baking dish, and preheat your oven to 356°F (180°C).
Whisk the eggs in a mixing bowl, skim off any foam with a spoon. Throw the foam away.
Mix the chicken stock with the egg until fully blended. The recipe calls for salted chicken stock; add salt to taste at this stage if you are using unsalted chicken stock.
Place a fine-mesh sieve or strainer over the baking dish and pour the egg mixture slowly through the sieve; this catches any egg bits and removes air bubbles. The clams should be partly covered but still peeking out.
Cover the dish with aluminum foil. And bake in the preheated oven for 15 minutes.
Check the custard after 15 minutes. It should be set around the edges and slightly jiggly in the center. It should not look watery or runny.
While the custard bakes, melt the butter in a small pan over medium low heat.
Once the butter has melted completely, add the minced garlic and chili powder (add a pinch of salt if you are using unsalted butter), cook for about 1 minute, stirring often, until the garlic smells fragrant.
Drizzle the warm garlic chili butter sauce over the top of the custard and clams.
Garnish with coriander.
