In a skillet, melt 1 tablespoon of butter over medium heat. Add the diced onion and finely chopped spring onions, cooking for about 3–4 minutes until fragrant and translucent.

In a separate saucepan, combine 2 tablespoons of butter and 2 tablespoons of all-purpose flour over medium heat, whisking continuously for 2 minutes to create a roux.

Gradually pour in 120 mL of whole milk, whisking until thickened, about 4–5 minutes.

Remove the béchamel from heat and mix in sautéed onions, crab meat, salt, and black pepper.

Transfer the crab mixture to a bowl and cover with plastic wrap. Chill in the refrigerator for at least 30–45 minutes.

After chilling, scoop the mixture and shape it into small patties, about 2 inches in diameter.

Set up a dredging station with flour, beaten egg, and panko bread crumbs.

Dredge each patty in flour, dip in egg, and roll in panko until well-coated.

Heat 1–2 inches of neutral oil in a frying pan over medium-high heat until it reaches 350°F (175°C). Fry croquettes for about 3–4 minutes on each side.

Transfer to a plate lined with paper towels to drain any excess oil and sprinkle with fresh parsley for garnish.