Prepare a hot grill. Skewer the slices individually. The shiitakes should have a scallion on each side. Lightly oil and season the satays and on a hot grill, mark and criss-cross both sides, about 4 to 5 minutes total. In a food processor, add 2 cups peanuts, shallots, garlic, chiles, kaffir, and lemon grass and puree smooth. Add sugar, lime juice and season. Drizzle in remaining oil then add the herbs. Check for seasoning.
Lay a bed of peanuts on a large plate. Serve the pesto in a bowl and surround with satays. Garnish with extra kaffir leaves or lemongrass.