Set an electric pressure cooker to the sauté function. Add the butter and onions and cook until softened. Stir in the ginger, garlic, garam masala, cumin, cayenne and ½ teaspoon salt. Cook about 30 seconds, until fragrant.
Add the chicken, tomato sauce, 1/2 teaspoon salt and ¼ cup cream to the pot and stir to combine.
Cover and set to pressure cook at high pressure for 8 minutes. Release the pressure manually.
Scoop the chicken out of the pot with a slotted spoon (cover to keep warm). Add the remaining ¼ cup cream to the sauce in the pot. Press the sauté or reduce button. Let the sauce simmer until slightly reduced and thickened, 8 – 10 minutes.
Add the chicken back to the pot. Add the cilantro and stir to combine.
Serve in bowls over rice or with naan flatbread on the side.