Prepare the court bouillon: Combine peppercorns, bay leaves, onion/leek, garlic clove, and thyme/oregano sprigs in a pot of water.

Bring the court bouillon to a boil and simmer for 15 minutes.

Add 1 teaspoon of salt and shrimp to the court bouillon.

Cook the shrimp below a boil for 2-3 minutes, until pink and cooked through.

Remove the shrimp from the court bouillon using a strainer.

In a separate bowl, combine scallions, garlic, lemon juice, white wine vinegar, kosher salt, fennel seed, coriander, dried chiles, cardamom, and lemon slices.

Let the mixture sit for 5 minutes.

Add the cooked shrimp to the bowl with the marinade ingredients.

Mix well to combine.

Add olive oil to the shrimp mixture.

Mix well to ensure all ingredients are coated.

Add chopped fresh oregano to the mixture.

Mix again to incorporate the oregano.

Serve the pickled shrimp cold or at room temperature, at least 5 hours later or ideally the next day.