Cut tuna into strips 1-inch high by 1-inch wide. Chill tuna in the fridge to air dry a bit.
Toast coriander seeds and fenugreek in a dry skillet. Grind with peppercorns in a coffee grinder or spice grinder. Place mix in a pie plate.
Meanwhile make the garnishes. For the chutney: in a food processor combine onion, cilantro, ginger, chili peppers, lemon juice and season with salt and fresh pepper. Blend til well combined. Cut pita bread into triangles and fry in hot oil. Drain on paper towel.
Heat a skillet til very hot. Roll tuna in the spice mix. Add a little oil to the pan. Sear the tuna on all 4 sides. Slice thin and serve with pita triangles and chutney. Sprinkle with more chopped cilantro.