For the Chicken Filling, mix oil and garlic salt in medium bowl. Add chicken; turn to coat. Grill chicken over medium-high heat 6 to 7 minutes per side or until cooked through. Cool slightly then finely chop. Mix chicken, katsu sauce, sugar and red pepper until well blended. Set aside.
For the Tamales, soak corn husks in hot water 30 minutes or overnight until soft and pliable. Melt lard in medium saucepan on low heat. Mix masa harina, oregano and garlic salt in large bowl until well blended. Add lard and stock; mix to form a moist dough. Drain corn husks and pat dry. Cut 2 of the larger corn husks into 12 thin strips for the tamale ties.
To assemble each tamale, spread 3 tablespoons masa dough into 4 1/2 x 4-inch rectangle at the wide end of husk. Spoon 2 tablespoons Chicken Filling in center of masa. Bring long sides of husk up to enclose filling with masa. Roll husk around tamale. (Do not roll husk into masa.) Fold up the narrow end of the husk, keeping the top end of the tamale open. Tie tamale with husk strip.
Pour 1 inch of water into large pot. Bring to boil. Stand tamales with open ends up in steamer basket. Cover tamales with a layer of remaining 4 husks. Insert steamer basket in pot. Cover. Steam on medium heat 1 hour or until husk peels away easily from tamale and masa is slightly firm. (Tamales will continue to firm up when removed from heat.)
For the Katsu Picante Sauce, place all ingredients in blender container; cover. Blend until smooth. Serve with tamales.