Rinse the fish under cold water, pat dry, and cut into cubes about ¾ inch in size. Place in a bowl or shallow dish and toss with the flour, a little salt, and pepper. Set aside.

Peel the shallot and garlic cloves and finely dice them. Rinse the chili pepper, slice it lengthwise in half, and cut into thin strips. Finely grate the ginger. Peel the carrot and cut into small matchsticks or thin half-moons. Rinse the sugar snap peas and either leave them whole or cut in half, depending on their size. Wash the bell pepper and cut into small pieces. Rinse the green onions and slice the green parts into rings or thin strips.

Trim off the hard, woody ends of the lemongrass and remove the outer, dry leaves. Split the inner, pale, tender part lengthwise and finely chop it.

Heat 1 teaspoon of oil in a pan or wok. Add the fish pieces and sear on all sides for 3–4 minutes until lightly browned. Remove from the pan and set aside.

Add the remaining oil to the wok. Sauté the shallots, garlic, ginger, and lemongrass for 30–60 seconds, then add the chili and vegetables and cook for another 2–3 minutes, stirring frequently.

Add the sugar and let it briefly caramelize, then stir in the red curry paste. Reduce the heat slightly and deglaze with the coconut milk and fish sauce. Let the curry simmer for 6–8 minutes.

Add the pieces of fish and let them simmer for another one to two minutes.

If needed, season the curry with salt and pepper, and serve with the spring onions and, if desired, fresh coriander.