Rinse the fish with water then place in a baking tray and rub with a bit of salt and with about 2 teaspoons of ground thyme or oregano, place some cut lemons inside and bake for 20 minutes at 350F.
Meanwhile, chop green and red peppers into small cubes, then mix crushed garlic with lemon juice, 5 teaspoons of ground thyme or oregano, the ground cilantro, the sumac, olive oil and salt to taste. This should yield a red paste that you would then mix with the chopped peppers.
Once the fish is baked, and while still warm, remove its bones and scales, pull its meat then place it in a baking tray and scoop the paste on top of it until it's all covered. You don't have to mix it, the paste will seep through naturally.
Bake again for about 10 minutes at 350F so the paste infuses well into the meat then serve hot or cold along with a side of Fattoush or your preferred salad.