Prepare the Napa Cabbage by removing tough outer leaves and cutting out the core. Finely shred remaining leaves.

Slice the fennel bulbs in half, remove the core, and thinly slice widthwise.

Salt the vegetables with kosher salt and let sit for 15 minutes.

Drain excess liquid from the mixture to retain some moisture.

Mix in flavor boosters: green onion, garlic, ginger, chile paste, fennel seeds, sugar, and rice vinegar.

Allow the kimchi mixture to marinate at room temperature for 2 hours.

Store the kimchi in an airtight glass container in the refrigerator.