Add <quantity>1<unit>gal</unit></quantity> of water to a large pot

Cut <quantity>1</quantity> garlic head in half horizontally

Trim and quarter <quantity>1</quantity> onion

Peel the onion quarters

Cut a leaf of dried kombu into a <quantity>3<unit>in</unit></quantity> x <quantity>2<unit>in</unit></quantity> piece

Add the onion, the garlic, the dried kombu leaf and <quantity>5</quantity> dried shiitake mushroom to the pot

Place the pot over medium heat and bring to a simmer for 30m, until the onion and garlic are translucent

Strain the liquid. The kombu dashi is ready

Add <quantity>1½<unit>qt</unit></quantity> of the kombu dashi to a pot over medium-high heat

Add <quantity>2<unit>tbsp</unit></quantity> of salt

Add <quantity>2<unit>cups</unit></quantity> of cooked rice and stir to combine. Bring to a boil

Scoop the foam from the surface with the help of a ladle

Lower the heat to medium and let the rice simmer for 15m until it resembles a loose risotto. Stir occasionally, making sure the bottom doesn't scorch

Plate the rice in small bowls

Add chopped scallions and white sesame seeds to taste. The rice porridge is ready

Enjoy it as a starter or serve it as a light meal with a poached egg!