Cut the salmon fillet into small cubes, peel the shrimp and remove the heads. Marinate salmon cubes and shrimp in lime juice mixed with salt and sugar for 1 hour.
Cut the onion into very thin feathers. Cut the bell peppers into thin slices. Remove seeds from chili, chop the pod.
Gently remove the pulp from half of the pomelo and divide it into pieces.
Mix seafood with pomelo pulp and peppers. Serve ceviche in half a pomelo, garnished with fresh herbs.