Combine the feta, Greek yogurt, olive oil, lemon zest, and lemon juice in a food processor or blender. Mix until smooth. Season with salt and pepper.
WONTONS:
Cut wontons in half so that they make a triangle. Heat vegetable or canola oil to medium heat. It should be hot enough that the wonton sizzles when placed in the oil. Cook 30 seconds or until brown, flip when the first side gets brown. Remove from oil and drain on a paper towel. Cook in small batches.
NACHOS
In a large skillet, heat 1 tablespoon of olive oil over medium-high heat. Season shrimp and crawfish with Greek seasoning. (I usually use peeled and cooked crawfish that have been frozen then thawed. I still add them with the shrimp in this step and heat through.) Cook 2 to 3 minutes on medium heat until cook through. Remove from heat and add the onion and peppers and cook until softened, about 5 minutes, season with salt and pepper while cooking.
Place the chips on a platter Top with shrimp, crawfish, red onions, bell pepper, black olives, and pepperoncini. Heat in oven 4 to 5 minutes to heat everything through.
Remove from oven, sprinkle feta, green onions, and tomatoes over the top. Serve immediately.