In a large, dry skillet over medium heat, toast the coriander and cumin seeds, stirring frequently, until they become fragrant and slightly darkened—approximately 3 to 4 minutes. Remove from heat, allow to cool briefly, and grind using a spice mill or mortar and pestle. Wipe out the skillet and set it aside for later use.

In a medium mixing bowl, combine the ground spices with the lemon zest, chili powder, 1 tablespoon of olive oil, and 1 teaspoon of kosher salt. Add the shrimp and toss to coat evenly. Allow the shrimp to marinate at room temperature for approximately 10 minutes.

In another medium bowl, combine the chopped cilantro, parsley, and oregano. Stir in the minced garlic, red wine vinegar, crushed red pepper flakes, 3 tablespoons of olive oil, and ¾ teaspoon kosher salt. Mix thoroughly and set aside.

Return the cleaned skillet to the stovetop over medium heat. Add the remaining 1 tablespoon of olive oil and the finely chopped shallot, along with a pinch of kosher salt. Cook for 3 to 4 minutes, stirring occasionally, until the shallots begin to brown lightly at the edges.

Add the marinated shrimp and any residual marinade to the skillet in a single layer. Allow to cook, undisturbed, for approximately 2 minutes to develop a sear. Turn the shrimp, add the vegetable or fish stock, and bring to a gentle simmer. Continue cooking, stirring occasionally, for 1 to 2 minutes or until the shrimp are pink and fully cooked through.

Remove the skillet from heat. Spoon the chimichurri sauce over the cooked shrimp and serve immediately with lemon wedges and toasted crusty bread on the side.