dumpling soup, wonton
餛 centers on a specific kind of filled dumpling served in soup, commonly known as wonton. The meaning is narrow and concrete, referring to the food itself.
餛 combines 飠 (food) with 昆, which likely contributes the sound. The character was created to name a specific food item, but the exact historical development is uncertain.
The food radical 飠 on the left tells you this is something to eat. The right side 昆 looks like a bowl with a lid and a spoon, perfect for serving dumpling soup.
For コン, imagine a steaming bowl of wonton soup that you eat with a cone-shaped spoon: cone -> コン, and the cone shape helps you scoop up the dumplings.
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steamed manjū; steamed mochi