In a large, heavy-bottom pot, heat the sesame oil over medium, and stir fry in the meat, until browned.
Add the onions and garlic, and stir-fry until the onions are translucent.
Add the doenjang and rice, and mix to coat.
Add the potatoes, eggplant, and water. Bring the broth to a simmer for about 20 minutes, and allow the porridge to reduce, while stirring to prevent sticking to the bottom. Add more water if necessary. The porridge will thicken, and the vegetables will soften.
Fold the spinach into the porridge in batches, until it's all wilted.
Finish with salt to taste, and serve with green onion as a garnish.