To make the five pepper sauce: Place the red onion, bell peppers, chile manzano and jalapeño in a medium heatproof bowl and set aside. Heat the peanut oil and sesame oil in a saucepan set over medium heat for a couple minutes. Once hot, pour in the vinegar, stir, and cook for a minute. Add the sugar, stir, and cook until it completely dilutes. Add the broth and the salt, stir, and cook for another 3 to 4 minutes, until the liquid has reduced and thickened. Remove from the heat. Pour it over the vegetables while hot. Add the lime juice, taste for salt, stir and let sit while you cook the fish.
Heat a couple tablespoons of peanut oil in a nonstick skillet set over medium-high heat. Season the fish fillets with salt and pepper to taste. Sear the fish for 5 to 6 minutes per side, depending on the thickness of the fish, or until it can be flaked with a fork.
Transfer the fish to a platter and dress with the five pepper sauce. Serve with warmed corn tortillas.