In a large cast iron skillet, heat olive oil to shimmering over medium-high heat.
Add onion and cook, stirring frequently, for about 5 minutes or until softened and some golden color starts to develop.
Add garlic, chilies, and ginger, and saute stirring, for a minute or two or until ingredients are softened, but garlic is not browned.
Add spices and saute, continuing to stir, for about 30 seconds. Stir in soy beans and tomatoes and heat through.
Add cashew powder and coconut milk, and simmer, stirring occasionally, for about 5-10 minutes to combine flavors. Reduce heat if necessary to prevent mixture from sticking.
Serve hot over cooked Basmati rice. Garnish with cilantro sprigs and cashew halves.
Alternatively, ladle the soy beans and sauce into bowls and top with a scoop of rice before garnishing as desired.
Note: Feel free to use other beans or lentils of your choice.

1 tablespoon olive oil
1 small-medium onion, cut into 1/4-inch dice
2 tablespoons garlic, minced
1 tablespoon very finely diced mild, medium or hot chilies
1 2-inch piece of ginger, peeled and very finely chopped
1/2 teaspoon yellow mustard seeds
1/2 teaspoon turmeric
1 tablespoon ground cardamom (start with about a teaspoon, if you choose, and add more to taste)
1 15.5 ounce can cooked black soy beans, rinsed and drained (you could use other bean or lentil)
1 medium tomato, cored, and cut into 1/4-inch dice
1/3 cup raw cashew pieces (roasted & lightly salted cashews are also fine), processed until almost powder
1 15 ounce can coconut milk
Garnish: sprigs of fresh cilantro and cashew halves
Accompaniment: cooked Basmati rice and, if desired, cooked pappadam