This was the first course in our cooking class in Cusco, Peru. The secret is to use a high quality, very fresh fish; and lots of fresh juicy lime. We can't get the same peppers here in the USA; so use a hot chili pepper of your liking instead.
The next tip is rubbing the bowl with the pepper ~ this imparts a lot of flavor to the fish before marinating.
The last tip is that it only marinates for a few minutes before you stop the "cooking" process by adding the fish or chicken stock.
We had lots of wonderful ceviche during our stay in Ecuador and Peru; this was, without a doubt, among the best.