In a wide pan over medium-high heat, toast the shrimp shells and heads in the EVOO, about 2 turns of the pan. Add leek, onion, lemon, garlic, peppercorns, bay leaf, and herb bundle. Sweat the vegetables for a few minutes. Add vermouth and reduce by half. Add the stock and bring to a boil. Reduce the heat to medium and simmer for 45 minutes. Strain the stock with a fine mesh strainer. Return the stock to the pan and bring to a boil. Reduce to about 1 ½ cups of concentrated stock.

In a bowl, combine garlic and EVOO. Add shrimp and salt them, toss, and refrigerate for 1 hour uncovered before preparation.

In a large pan over medium-high to high heat, heat 2 tablespoons olive oil, 2 turns of the pan.  Add the shrimp and sear for 2-3 minutes, then turn, season with salt and pepper, and cook for 1 minute more. Remove the shrimp from the pan. Add the remaining olive oil, another 2 turns of the pan. Add the minced celery and garlic and stir for 1 to 2 minutes. Add chili paste, stir. Add the vermouth and let it absorb. Add stock and let it bubble and reduce for 1 minute. Then add the butter and parsley and swirl the pan. Add the shrimp back to the pan and turn to coat. Cook the shrimp through two minutes more and douse with lemon juice. Add parsley.

To serve, in each of 4 shallow bowls, place a charred slice of toast topped with 5 to 6 shrimp and a quarter of sauce.