How to keep chicken livers intact?
As you note, the recipe I was able to locate for Nando's spicy chicken livers (with tagliatelle pasta) did the trick. While that version calls for veg (marrow/zucchini) and pasta, here are the directions for the chicken liver and sauce.
Heat 5 Tablespoons of olive oil or butter over a medium heat. Add the chicken livers and sauté for 4 minutes. Add one cup of Nando’s sauce to the chicken livers and allow to cook for another 2 minutes, then remove from the heat.
In announcing the new Mozambican Paprika flavor, Nando's head of food, Pascale Sobiecki, revealed that the recipe contains

coconut, lime, lemon, garlic, tomato, onion, parsley and rosemary and, of course, paprika – no less than three different kinds, one of them smoked.
Because it’s Nando’s, there is a touch of African bird’s eye chilli – but only a hint. On the Nando’s PERi-Ometer, Mozambican Paprika is slightly hotter than Lemon and Herb (which also contains chilli, incidentally), but milder than our Mild flavour.

Until it's available, you might have some fun trying to create your own version of the sauce.