1. Blend the rosemary, thyme, and 4½ cups of water in a blender until the herbs are finely ground. Strain through a fine-mesh sieve into a large saucepan, pressing on the herbs to extract as much liquid as possible. Then, discard the solids. Add the zest, ginger, 1 Tbsp. salt, and the potatoes to the pan. Bring everything to a boil, and then reduce the heat to maintain a steady simmer. Cook about 20 minutes, until a knife can easily pierce a potato.

2. Thinly slice a quarter of the chile and set aside. Remove the stem and seeds from the remaining chile and chop finely. Combine the chopped chile with the mint, basil, dill and marjoram in a small bowl. Cut three ½ –inch-deep slits crosswise in each fillet. Stuff ½ tsp. of the herb mixture into each slit, being careful to not get it on the skin. Season the fish with salt.

3. Heat half of the oil in a large skillet over medium-high heat, until almost smoking. Add 2 fillets, skin side down, and cook about 3 minutes, until golden-brown and crisp. Carefully flip, and cook until the fish is just cooked through, about 6 minutes longer. Transfer to a warm plate. Repeat with the remaining oil and fillets.

4. Add the spinach and sliced chile to the potatoes and broth. Cook, stirring, until the spinach wilts. Divide the potato mixture and broth among shallow bowls. Top with the fish and season with a little salt. Serve with lemon.