Charred Beef and Spinach Hand Roll

Name: Charred Beef and Spinach Hand Roll
Ingredients: 1 (8-ounce) fillet of beef tenderloin; 1 tablespoon canola oil; Coarse sea salt; 2 tablespoons coarse ground black peppercorns; 2 tablespoons coarse ground white peppercorns; 2 tablespoons coarse ground green peppercorns; 2 tablespoons coarse ground pink peppercorns; 1 tablespoon coarse ground Szechwan peppercorns; 1 lemon, juiced; 1 tablespoon Japanese soy sauce; 2 tablespoons grapeseed oil; 1 pound baby spinach leaves; 1 tablespoon freshly grated wasabi or wasabi paste; 3 tablespoons creme fraiche (may substitute sour cream); Sushi Rice, recipe follows; Nori sheets; 4 cups sushi rice (Calrose/short grain); Water, up to Mount Fuji; 1 cup rice wine vinegar; 1/4 cup mirin; 1/2 cup sugar