First, gather all your ingredients and prepare them in the right amounts. That makes it so much easier and more fun and you're less likely to forget anything.
Remove the hard stems from the kale, cut into smaller pieces and wash it. That works well in a large salad spinner.
Cut the potatoes into 1 cm slices and boil them in salted water for 10 minutes.
Meanwhile, cut the tofu into roughly 1 cm cubes and fry it in a Dutch oven or large wok pan in olive oil over medium to high heat for about 4 minutes without stirring.
Finely chop the onions, then stir the tofu and add the onions. Fry for another 2-3 minutes.
Meanwhile, drain the potatoes, give them a shake in the sieve and let them steam out.
Remove the tofu and onions from the pan, add a little more oil, then add the potatoes to the pan and again do not move them for a few minutes until the bottom side is nicely browned.
Now stir the potatoes so they can brown a little from the other side and place the kale on top. Then add the tofu and onions, mustard, salt, and pepper. The pan will now be very full. Slowly stir, first the top and then also the bottom, as the kale wilts. This takes about a minute. Do not stir for too long, the kale should still have some texture. Serve immediately.