Diagnose what a dish is missing

You have tasted it four times and it is fine but flat.

I have a dish that tastes not quite right. Help me work out what it needs.

Walk me through the diagnosis in this order, asking me to taste after each:
1. **Salt.** Almost always the answer. How to tell the difference between under-salted and genuinely flat.
2. **Acid.** Which acid suits this dish, and the risk of adding the wrong one.
3. **Fat.** Whether richness is missing and what to add given what the dish already is.
4. **Sweetness**, and whether it is needed to balance bitterness or acidity rather than to make it sweet.
5. **Umami and depth.** What I could add that fits the dish rather than making everything taste of the same one ingredient.
6. **Heat, bitterness, aromatics, texture.** The less common culprits, including the possibility that the problem is that everything is the same soft texture.

For each, give the specific amount to add first and tell me to taste before adding more. If you think it is simply undercooked or overcooked, say so instead.

What the dish is:
What I have already put in it:
How it tastes to me:

When it goes wrong. It split, sank, or tastes flat. Work out the cause and the fix while dinner is still rescuable.