Step 1

Melt the butter in a large Dutch oven or deep skillet over medium-high. Add half of the shallots, season with salt and pepper and cook, stirring occasionally, until fragrant and starting to brown at the edges, 4 to 6 minutes. Stir in the garlic and ginger, and cook until fragrant, 1 to 2 minutes. Remove from the heat.

Step 2

Add the olive oil and gochugaru, stirring constantly until fragrant, about 30 seconds. Raise the heat to high and add 2 cups water. Scrape the stuck-on bits off the bottom of the pot with a wooden spoon, and bring the broth to a boil.

Step 3

Add the broccoli rabe and nestle in the shrimp. Reduce the heat and gently simmer the shrimp, turning them once halfway through, until pink and just barely cooked through, 2 to 3 minutes. The broccoli rabe should be bright green and considerably wilted.

Step 4

Stir in the remaining shallots, the radishes, fish sauce and sugar. Taste for seasoning, adding more salt, gochugaru, fish sauce or sugar as needed.

Step 5

Serve the stew in wide bowls with a plate on the side for the shrimp shells, and some crusty bread or steamed rice for sopping up the aromatic juices.