Heat a large pot over medium heat and add olive oil. Add in leeks with a 1/4 teaspoon of salt and pepper, tossing to coat and allowing to cook until softened, about 5-6 minutes. Add in garlic, red pepper flakes, shrimp and remaining salt and pepper. Stir well and cook for an additional 4-5 minutes, until shrimp is pink. Add in the brandy and sherry, cooking for 5 more minutes then turn off heat.

Transfer the entire mixture to a food processor (or a large bowl first, whichever is easy), then pulse until the shrimp and leeks are coarsely chopped but not pureed. Return the pot to the stovetop over medium heat. Add in butter, and once sizzling add in flour, whisking well to create a roux. Cook for 2-3 minutes until golden brown, then add in the half and half and heavy cream, stirring well until slightly thickened, about 5 minutes or so. Whisk in the stock, tomato paste and asiago, stirring until the cheese melts and the soup is smooth. Add the shrimp mixture back into the soup and reduce the heat to low, stirring well. Let sit over low heat, stirring occasionally, for about 10-15 minutes. Taste and season additionally if needed. Serve with additional asiago, fresh herbs and toasted bread.