Heat tortillsa and keep soft. (Nuke or steam) Bring water to boil, add lemon jjuice, peppercorns, salt, and cook 2 min. Add shrimp, cook till pink and done, drain cool and peel. Prepare chipolte butter--Puree together butter, 6 shrimp and 1.5 T chipoltes, and set aside at room temp. Just before serving, toss remaining shrimp with rest of chipolte puree, and heat in skillet. Put three tortillas on plate, add 8 shrimp, top with butter. Sprinkle with green onions, and serve with the Ranchero Sauce. Garnish each plate with avocado slices.