Soak mung beans in water overnight. Drain.
Heat oil or ghee in a heavy-bottomed pressure cooker. Sauté onions and garlic over medium heat for 2 to 3 minutes, stirring frequently until onions soften. Add turmeric, cumin, coriander, black pepper, fenugreek, and fennel seeds. Stir constantly over medium heat until spices are aromatic.
Add sweet potato, mung beans, water or vegetable stock, ginger, kombu, and salt.
Cover and secure the lid (put pressure valve in place if your model requires this). Bring to high pressure and cook for 15 minutes. Stop the cooking and allow pressure to release naturally before opening.
Serve hot, garnished with fresh chopped cilantro and freshly squeezed lime or lemon juice.
Here are some ideas for variations (which are endless!).
1) Replace mung beans with red lentils.
2) Add chopped plum tomatoes, finely chopped kale stems, finely chopped carrots or other root veggies of choice before cooking.
3) After cooking, add chopped leafy greens (kale or Swiss chard) and simmer for 2 to 3 minutes until greens are tender.