Pulse chilies, garlic, onion, tomato, salt in food processor. Keep coarse.
Heat 1–2 tbsp vegetable oil over medium.
Add paste and spread thin.
Cook 6–10 minutes, stirring occasionally.
It should thicken and darken slightly; oil may lightly separate.
Remove from heat.
Stir in vinegar and lime.
Texture: thick, spoonable, not wet.
Set aside.