Heat oil in a pressure cooker and add ginger, garlic, and green chilli paste. Fry for 30 seconds over medium heat, until fragrant. Then add the sliced onions and cook until they are soft and translucent. This will take about 5 minutes.
Now add the powdered spices, red chilli, coriander, turmeric, and garam masala. Also, add a dash of water to avoid burning and stir fry for a minute or two.
Increase the heat to medium-high and add the beef to the pressure cooker. Fry the beef along with the spices, stirring occasionally until oil oozes out. This will take about 8 to 10 minutes.
Once you see oil on top, add a cup of water to the pressure cooker and stir well. Put on the lid and pressure cook for 15 to 20 minutes or until done. Allow the pressure to release completely.
Now open the lid add the potatoes and tomatoes to the pressure cooker and stir to combine them with the beef and spices.
Put on the lid and pressure cook for one or two whistles and then turn off the heat.
Once the cooker is cooled, open the lid and check if the beef is tender and the potatoes are cooked through.
Taste and adjust the seasoning. If desired, you can add a squeeze of lime juice.
Serve the beef curry with potato over steamed rice or with warm naan bread. Garnish with fresh coriander or mint leaves.