Scoop the green beans into a microwave-safe bowl, sprinkle with a couple of tablespoons of water, cover with plastic wrap (poke a couple of holes in it to allow for steam to escape) and microwave on full power for 2 ½ minutes, until the beans are tender. When they are cool enough to handle, cut them into 1-inch pieces. Set aside.
Measure the oil into a very large (12-inch) skillet and set over medium-high heat. If the skin of the two halves of the trout is still connected, cut them apart if you like, making two fillets. Sprinkle the fish generously with salt and lay skin-side up in the hot oil. Cook until golden underneath, 2 to 3 minutes. (If they don’t fit comfortably in the pan, cook them in 2 batches.) Use a spatula to turn the fish and cook for a minute longer, until the flesh separates from the skin (use a corner of your spatula check at one edge). With the spatula, transfer a pair of fillets to each of 4 dinner plates, flipping them skin-side down.
Reduce the heat under the skillet to medium. Add the green beans and cook for a couple of minutes until they are beginning to brown. Add the garlic and cook a few seconds until fragrant, stirring constantly. Pour the broth into the skillet and add ½ teaspoon salt and the chile.
Increase the heat to high and cook for a minute or so to concentrate the broth. Then add the macadamias, cilantro and lime juice and mix well. Taste and season with salt, usually another ½ teaspoon. Spoon a portion over each fillet and dinner’s ready.