Bring a large pot of lightly salted water to a boil. Add the spaghetti and cook until tender, about 7 minutes. Drain, stir in a tablespoon of butter and set aside.
Melt 1 tablespoon of butter in a frypan over medium heat. Add the onion and garlic and cook until lightly browned. Lay the fish fillets in the frypan and cook until golden on each side, about 5 minutes. When the fillets are starting to be done break them into pieces with a fork or spatula.
Add the remaining butter to the frypan and stir in the escargot. Cook and stir for about 4 minutes. Escargot cooks fast like prawns, so watch it. Remove from the heat and season with parsley, oregano and basil. Top with a sprinkling of Parmesan cheese.