Peel the shrimp, discard the veins, and put the shells and heads in a saucepan with a bit of oil.
Turn the heat to medium-high so they get some color.
Add the rest of the oil and possibly break/crush them with a wooden spoon to release all the flavor.
Let it simmer for 15-20 minutes.
Pour the oil into a jar through a strainer. Discard the shells and heads.
Cool the oil to room temperature. Use the freezer/refrigerator if you're in a hurry.
Put the egg yolk in a bowl and add salt.
Whisk well and add mustard and vinegar and whisk again.
Now add the shellfish oil while continuing to whisk. Start with very little, and as it thickens, gradually add more.
Continue and possibly use a bit more oil than the recipe states if you don't think it's thick enough.
Season to taste with lemon juice, freshly ground pepper, and possibly more salt.
Refrigerate until needed.
Bring water and vinegar to a boil in a large saucepan.
I usually crack the eggs separately into a slotted spoon. This removes the unwanted part of the egg white, ensuring a nicely poached egg.
Place the eggs in a small ramekin/bowl separately.
Bring the saucepan to a boil and reduce the heat so it's just below the boiling point.
Create a whirlpool with the wooden spoon and gently pour the egg into the center of the saucepan. The whirlpool helps gather the white around the yolk.
Cook for about 3-4 minutes, depending on the egg's size.
I usually have a bowl of cold water (often with ice cubes) next to the stove. Put the egg there as soon as you take it out and about 30 seconds later, place it on a paper towel/clean cloth.
Repeat the process with the other 3 eggs.
Make sure the peeled shrimp are well dried (I usually use a clean cloth) and are out of the refrigerator for about 15 minutes before frying. Both help ensure they fry nicely instead of "boiling" in the pan.
Heat the pan on high (I use 12 out of 14 on my stove). Add butter/oil/ghee to the pan and fry them for about 1 minute on one side and 30 seconds on the other side.
Take them off the pan, and they are ready to serve.
Toast your bread in the toaster or oven. An indulgent version is to fry it in butter on the pan.
Spread the shellfish mayonnaise on the bread.
Place the shrimp on top along with the parsley, summer truffle, and finally the poached egg.
Add a little flaky salt and freshly ground pepper on top and enjoy a fantastic appetizer.
