For the kangaroo steak, first prepare the sauce. For the sauce, chop the onion and sauté briefly in a small saucepan. Wash, pit and dice the plums, sauté for 5 minutes and deglaze with wine.
Stir in the vanilla sugar, Piri Piri sauce and cornstarch as needed, set aside and keep warm.
For the polenta corners, boil a small pot with 500 ml of water and bouillon cubes. After about 5 minutes, mix in the cornmeal and cook on the lowest setting for about another 10-15 minutes.
Keep stirring so that the porridge does not stick. Season to taste. Line a baking tray with baking paper, spread the porridge about 2 cm thick and sprinkle with cheese.
Bake for about 30-35 minutes at 200 g. When crispy enough, remove from oven, cut into triangles or squares and let cool.
Heat some oil in a frying pan and sear the salted steaks as desired (mine were medium). Arrange on plates and top with sauce.