Here are the spices. You can see the fenugreek seeds on the top left. They're very bitter. I know this because I ate one raw. Bleah. You can find them at specialty stores or at the bulk store in the spice section.
The finished dish.
1 cup red split lentils
2 1/2 cups water
1/2 teaspoon ground turmeric
2 large potatoes, diced
2 tablespoons canola oil
1/2 teaspoon mustard seeds
1/4 teaspoon fenugreek seeds
1 teaspoon curry powder (mild or hot)
1 onion thinly sliced
2 cups green beans cut into 1inch pieces
1/2 teaspoon chili powder
1 tablespoon lemon juice
Rinse the lentils in cold water until the water runs clear. Place the lentils, water and turmeric in a pot and boil for 20 minutes or until lentils are tender. In the meantime, boil the potatoes just until tender. Drain both.
In a large pan, fry the seeds and curry over medium heat for 2 minutes. Add the onion and green beans and cook for another 7 minutes. Add the drained potatoes and cook for another 2 minutes. Stir in the lentils, salt, chili powder and lemon juice. Cook just to heat through. Serve with plain yogurt.
Adapted from Best Ever Indian Cookbook.