Three things going at once here, and none of them are hard. Curry marinated chicken thighs for the barbecue, coconut rice on the stove, and a quick pickled cucumber salad that does the heavy lifting on balance.
The salad is what makes this. Sweet sharp pickling liquid over cucumber, coriander and fresh chilli, chilled, sitting next to rich coconut chicken. Without it the plate is heavy. With it the whole thing lifts.

Vinegar and sugar into a small saucepan, simmer for fifteen to twenty minutes until it reduces and thickens slightly. This is the longest single step so it goes first and everything else happens while it bubbles away.
Three quarters of a cup of caster sugar to one cup of vinegar sounds like a lot of sugar. It is, and it needs to be. That sweetness is balancing the curry and the coconut on the other side of the plate.
Pour it over the cucumber while it is still warm, then get the bowl into the fridge. Cold is part of the point.
Lebanese cucumbers, flesh removed, sliced into half moons. Run a teaspoon down the middle and scoop out the watery seedy centre before you slice.
Skip that and the seeds release liquid into the pickling mixture and dilute it. You end up with a watery salad instead of a sharp one. It takes about a minute for all six.
Curry paste, coconut milk, shredded coconut and chopped coriander into a bowl, then the chicken thighs in and tossed to coat.
Any curry paste works. Red, green, yellow, whatever is in the fridge. They all sit well against coconut and none of them are wrong here.
Thighs rather than breast, and it matters on a barbecue. Thighs carry enough fat to survive direct high heat without drying, and the marinade has coconut milk and shredded coconut in it that will catch and char. On breast meat you would be racing the clock. On thighs you have room.
Use the coriander roots as well as the leaves if you have them. The roots carry more flavour than the leaves do and they are usually thrown away.

Rinse the jasmine rice properly first, until the water running off it goes mostly clear. That washes off surface starch and it is the difference between separate grains and a sticky mass.
Equal parts coconut milk and water, plus salt. Bring it to a boil, drop to low, cover, twelve to fifteen minutes until the liquid is gone. Then off the heat with the lid still on for five minutes before you fluff it.
That five minutes of sitting is not optional. It lets the grains finish steaming in their own heat and firm up. Fluff too early and you get mush.
Five to seven minutes each side over a hot barbecue or in a hot pan, until cooked through with proper char on the outside.
The shredded coconut in the marinade will darken fast. Some of that is good and it tastes toasted. Watch it though, because coconut goes from browned to burnt quickly.
Chicken, coconut rice, and the chilled cucumber salad alongside. Spoon a little of the pickling liquid from the bowl over everything.
Leftovers work well the next day, though the salad softens. Keep the components in separate containers rather than plated together.
The cucumber salad holds a day in the fridge and arguably improves after a few hours. Any longer and the cucumber goes limp and loses its snap.
A ridged grill pan over high heat gives you similar char. A regular frying pan works too, though you lose the grill marks and some of the smokiness.
Barbecued coconut curry chicken thighs with jasmine coconut rice and a quick pickled cucumber and chilli salad.
The source recipe does not state times or servings; prep, cook and serving counts here are estimated from the method. Chicken should reach an internal temperature of 165F / 74C. Scrape the seeds from the cucumbers before slicing so they do not water down the pickling liquid. Store components separately if keeping leftovers.