Revenge is a dish best served cold; English Essay

Revenge is a dish best served cold.Have you always forgiven your enemies?
May i know what kind of essay is this and how do i start?

"Revenge is a dish best served cold" is an idiom meaning that it is very satisfying to get revenge a long time after the event for which you want revenge. So, this is about keeping the your grudges (may be for a very long time) until the right time comes for you to take the revenge. So, in my view, this essay is about taking revenge and in particular waiting patiently until the right moment prompts.

Is this a discussive ,arguementative , expositionary or a narrative essay?

This essay can be adapted to any of the rhetorical modes: descriptive, expository, narrative, or persuasive.

It all depends on how you approach the prompt. For example, you can extol the virtues of forgiving others (including your enemies) and segue into a narrative style essay which bears out a resonant idea to effect the theme of force by show of example. Or, you can answer the question and proceed to qualify the merits of forgiveness along with the alternatives and what all the options entail, thereby building support for your nuanced position as you set the terms of the argument. You may also delve into the legal, moral, and psychological spheres while you address the idea of revenge and forgiveness from an explanatory standpoint.

Finally, one could describe revenge, forgiveness, and the scope of how they might interrelate directly or how they relate otherwise, conceptually.