M: I have a bunch of coconut rice. That is, I made it with coconut milk and coconut water, along with a little sugar and salt. Can I turn this into fried rice?
G: Yes. Coconut rice can make very good fried rice. The main difference is that the coconut milk, coconut water, and sugar push it toward a slightly sweet, richer flavor, so you want the other ingredients to work with that rather than treating it exactly like ordinary Chinese-style fried rice.
The biggest practical issue is the same as with any fried rice: you want the rice cold and relatively dry. If it's freshly cooked, spread it on a sheet pan or large plate and refrigerate it uncovered for a while. Leftover refrigerated coconut rice is ideal. Coconut milk adds fat and can make the grains a little more prone to clumping, but that's not a problem—break the clumps apart before frying.
I'd take it in a Southeast Asian/tropical direction:
One thing I'd avoid is adding more sugar. You've already got the sweet component built into the rice. In fact, depending on how much sugar you originally used, I'd emphasize salty, savory, acidic, and possibly spicy ingredients to counterbalance it.
And there's actually a useful frying advantage here: the small amount of sugar and coconut solids can brown, giving you some nice toasted/caramelized bits. Just keep an eye on the heat because that also means coconut rice can go from browned to scorched somewhat faster than plain rice.
So yes—this isn't merely a way to dispose of leftovers. Coconut fried rice is a perfectly coherent dish, and your rice has already done half the flavoring work for you.
M: Um, in the middle. Um, would it be possible to make something like an appropriately diluted soy oil that had the right proportions for fried rice? And if so, what are the proper proportions? I am screwing around because I have a lot of rice and I really, I'm kind of enjoying it, but I don't think I'm doing it quite right. Like, I don't know how much oil I should add for how much rice and how much soy sauce to add when.
G: Yes—and I think a pre-mixed “fried-rice seasoning liquid” would actually be useful while you're experimenting. But I would not mix the soy sauce directly into the frying oil: soy sauce is water-based and won't stay mixed with oil, and they serve different jobs at different times.
For your coconut rice, I'd start with this repeatable ratio per 1 cup of cooked, cold rice:
Heat the pan first, then add the oil. Add your egg/vegetables/etc. as appropriate, then the rice. Break the rice apart and toss it in the oil.
Give the rice a little time to actually fry before adding the soy sauce—roughly 1–2 minutes in a hot pan. You're trying to drive off moisture and get some direct contact between rice and hot metal.
Then add the soy sauce around the exposed hot surface of the pan rather than dumping it onto the middle of the rice. Give it several seconds to sizzle and reduce, then toss it through the rice. That helps prevent the rice from simply absorbing a puddle of watery soy sauce and steaming.
For example, if you're screwing around with 3 cups of your coconut rice, I'd measure out about 2 tablespoons neutral oil and 2 tablespoons soy sauce. Use the oil at the beginning and keep the soy sauce waiting in a little cup until the rice has fried.
There's also a very useful diagnostic here:
Greasy rice → too much oil.
Wet/soft rice → too much sauce or sauce added too early.
Dry but bland rice → probably needs more seasoning, not more oil.
Rice sticking/burning → possibly too little oil, but also possibly
insufficient heat control or overcrowding.
And because yours is coconut rice, I'd deliberately start a little conservative with both. Coconut milk has already supplied fat, sugar, and flavor that ordinary leftover white rice doesn't have.
少(すこ)しずつ足(た)す — add it little by little — is particularly appropriate here, because you can always give the finished rice another teaspoon of soy sauce, but you can't take it back out.