Soak the dried red chili in warm water for 10 minutes, then drain.
Add all ingredients, except the butter and the virgin olive oil into a blender or food processor, and puree them.
In a saucepan, heat the butter and the oil, than add the chili tomato puree and bring the puree to boil. Simmer for 20 minutes or until the sauce slightly thickens.
Remove the basting liquid from the heat and set aside.
For the tilapia fillet:
In a bowl, combine the mayonnaise with the lime juice and marinate the Tilapia fillet with this mixture for approximately 20 minutes.
Remove the fish fillet from its marination and season with sea salt and pepper from the mill.
Place on a well oiled grill or BBQ rack over low heat and brush well with the basting liquid over the top of the fish fillet.
Turn over the fish frequently brushing the top side of the fish with the basting liquid just as often.
Grill until the fish is just done and still moist and serve immediately.