If you are using dry beans, then soak them overnight or at least 8~9 hours. Pressure cook them or boil them until tender. Drain and keep them ready.
Heat 2tbsp oil in a pan, add the cumin seeds and once they start to splutter, add the onions and cook till translucent and slightly turning brown around the edges.
Add ginger+garlic paste and cook for 1 minute stirring constantly.
Next add tomato paste along with ½ cup water and the dry masala powders (coriander, cumin, aamchur & red chili powder). Mix well, cover and cook till the oil leaves the side, about 5~6 minutes.
Add the kidney beans along with salt and ½cup more water. Bring to a boil, then lower the heat and simmer covered for 10~12 minutes or until the curry thicken slightly. Mash the beans to thicken the curry further.
Garnish with chopped cilantro and serve over steamed rice.