Soak clams in water to remove sand, then scrub shells clean.

Chop cabbage into bite-sized pieces, slice yellow bell pepper into thin strips, and slice garlic thinly.

Boil water in a pot, cook frozen udon noodles according to package instructions, then rinse in cold water and drain.

Heat salad oil in a pot, add garlic, and sauté until fragrant. Add clams, cabbage, and bell pepper, and stir-fry.

Add soy-based dashi and water to the pot, then simmer until clams open.