Cut squid tubes into rings. Cut large tentacles in half the long way, leave small ones whole. Clean/devein shrimp. Halve scallops (depending on size). Remove crawfish tails from heads, clean/devein the tail meat.
Add seafood & buttermilk in a zip-lock & sit in refrigerator overnight or at least 12 hours.
--Start Vinaigrette-- (Day before)
2 TBSPs olive oil, 1 TBSP garlic, sauté.
Add crawfish heads, shrimp tails/shells, 1/2 cup of white wine. Cook for several minutes until reduced. Squeeze juice from crawfish heads into liquid (great flavor) & throw away the heads. Strain & place in the refrigerator.
--Cook seafood--(2-Hours before)
Rinse seafood of buttermilk & pat completely dry. Separate into different types-squid, shrimp, etc…
Add 2-TBSPs of oil & garlic, sauté over med heat (careful not to brown).
Increase heat to med-high & add scallops. Sauté just until opaque (careful not to overcook)-Place in bowl.
Add 2-TBSPs of oil & shrimp sauté until they curl & turn pink-Place in bowl w/ scallops.
Add 2-TBSPs of oil & squid sauté-Place in bowl.
Add 2-TBSPs of oil & crawfish sauté-Place in bowl.
Place the cooked seafood in the refrigerator to chill completely (at least 2 hours)
Finish vinaigrette; add ¼ cup olive oil, 1 lemon's juice, salt & pepper to taste - wisk together. In a serving bowl, mix cooked seafood, diced tomatoes, diced avocado, vinaigrette, pepperoncini, olives, Old Bay, parsley & vinaigrette. Mix to combine & serve.