1/2 cup plus 2 tablespoons (about 1/2 ounce) jasmine tea leaves
1/4 cup hot water
Four 6- to 7-ounce pieces of lamb tenderloin
1/4 cup blanched whole almonds
3/4 cup crustless fresh brioche crumbs
2 tablespoons unsalted butter, softened
1 teaspoon finely grated lemon zest (preferably from a Meyer lemon)
Pinch of cayenne pepper
Salt and freshly ground pepper
2 tablespoons extra-virgin olive oil
2 cups shelled fresh or frozen petite peas (10 ounces)
3/4 cup chicken stock or canned low-sodium broth
In a small heatproof bowl, cover 1/2 cup of the jasmine tea leaves with the hot water and let stand for 5 minutes, or until the tea has absorbed the water. Spread the tea between two layers of dampened cheesecloth. Wrap the lamb loins in the cheesecloth and refrigerate for 2 to 4 hours.
In a mini processor, grind the remaining 2 tablespoons of tea to a powder and transfer to a medium bowl. Grind the blanched almonds until fine and add to the bowl. Add the brioche crumbs, butter, lemon zest and cayenne, season with salt and pepper and stir to form a dough-like mass. Working on a sheet of plastic wrap, pat the mixture into a 6-inch square about 1/4 inch thick. Wrap with plastic and refrigerate until firm.
Preheat the oven to 450°. In a medium saucepan, heat 1 tablespoon of olive oil. Add the peas and cook over moderate heat for 1 minute. Pour in the stock; bring to a boil. Cover and simmer the peas until tender, about 5 minutes. Pour the peas and stock into a blender and puree. Strain the puree through a fine sieve into a small saucepan; season with salt and pepper.
Remove the tea-crumb mixture from the refrigerator and cut it into 4 squares. Unwrap the lamb and rub off any bits of tea. Season with salt and pepper. In a large ovenproof skillet, heat the remaining 1 tablespoon of olive oil. Add the lamb and cook over moderately high heat until browned all over, about 6 minutes. Press a tea-crumb square onto each piece of lamb and roast in the oven for 8 to 10 minutes, until the crumbs are crisp and browned and the lamb is medium rare. Transfer the lamb to a carving board and let stand for 5 minutes.
Reheat the sweet pea sauce and spoon it onto 4 plates. Slice the lamb, arrange on the sauce and serve at once.
The tea-crumb mixture and the sweet pea sauce can be refrigerated overnight.