Start by blending the onions, garlic, ginger, and scotch bonnet (or chili flakes) with a small splash of oil until smooth.
Heat a generous amount of oil in a deep pan over medium heat. Pour in the blended mixture and cook, stirring often, until it thickens and darkens—this takes about 15–20 minutes.
Stir in the tomato paste and continue cooking for another 5–10 minutes, until the oil begins to separate and the mixture is very fragrant.
Add the ground dried fish and dried shrimp, along with salt and a seasoning cube if using. Mix everything together well.
Lower the heat and let the sauce simmer gently for another 15–20 minutes. Stir regularly to prevent burning. The sauce should become dark brown, rich, and deeply flavored.
Let the shito cool completely, then transfer to a clean jar. Make sure a layer of oil sits on top to help preserve it in the fridge.
