Combine broth, ginger, lemongrass, lime juice, soy sauce, mirin, red pepper flakes, and sweet chili jelly in a large, heavy bottomed saucepot with a lid and stir. Bring to a simmer over medium heat and cook for 3-5 minutes, until the ginger and lemongrass release their odor and chili flakes begin to bleed color into the broth.
While the broth is developing flavor, salt both sides of the chicken thighs with a pinch or two of salt each. If desired, strain flavored broth using a collander into a large bowl to remove chunks of lemongrass and ginger, then pour broth back into the warm saucepot.
Add rice, chicken thighs, and coconut milk, taking care to scrape coconut fat in with the rest of the can. Stir to combine, then cover with a lid. Cook 10 minutes over medium heat.
Meanwhile, remove the stalks of the collard greens and roughly chop them into approximately 1" thick pieces. Add chopped collards and cover. Cook another 20 minutes or so, until rice is al dente and chicken thighs register at least 155°F on a thermometer. Serve immediately. Keeps well in the fridge for up to one week.