The process is pretty much the same regardless of whether you use a stove-top pressure cooker or an electric one. The only difference is that your cooking time under high pressure will be slightly shorter with the stove top cooker than with an electric cooker (e.g. 30 minutes vs. 35 minutes).
In a large bowl, combine cubed beef, chili powder, and salt.
Press the “Sauté” button on your Instant Pot and add the ghee to the cooking insert. Once the fat’s melted, add the onions and sauté until translucent. (If you’re using a stove top pressure cooker, melt the fat over medium heat and sauté the onions.)
Stir in the tomato paste and garlic, and cook for 30 seconds or until fragrant.
Toss in the seasoned beef, and pour in the salsa, stock, and fish sauce.
Cover and lock the lid, and press the “Keep Warm/Cancel” button on the Instant Pot. Press the “Manual” or "Pressure Cook" button to switch to the pressure cooking mode. Program your IP to cook for 35 minutes under high pressure. If your cubes are smaller than mine, you can press the “minus” button to decrease the cooking time. Once the pot is programmed, walk away. (If you’re using a stove-top pressure cooker, you won’t have all those buttons to press. Just cook on high heat until high pressure is reached. Then, reduce the heat to low to maintain high pressure for about 30 minutes.)
When the stew is finished cooking, the Instant Pot will switch automatically to a “Keep Warm” mode. If you’re using a stove-top pressure cooker instead, remove the pot from the heat. In either case, let the pressure release naturally (~15 minutes).
Unlock the lid and season to taste with salt and pepper. At this point, you can plate and serve—or store the beef in the fridge for up to 4 days and reheat right before serving.
When you’re ready to eat, top the hot stew with cilantro and radishes.