This is a typical Brazilian dish made of beef short ribs cooked in with pieces of cassava (yucca) root, a tuber root veg very close in flavour and texture to potatoes. You can find cassava root at African or Latin American shops, and beef short ribs through your local butcher.
Wow this was like being in Brazil! My only modifications were using frozen mandioca and salting in a few more instances along the cook. Frozen cassava added some time. This came out quite authentic and was approved by an actual Brazilian. A little fresh parsley torn over the top at serving makes a nice presentation. The mandioca starches combine with the short rib's collagens to make a broth unlike any other. That's where the name comes from. Cow in the mire. - 09 Aug 2016 (Review from Allrecipes UK & Ireland)