No cassava in Eastern European lands where I am from :D But I saw many cassava plants in rural Laos.
Thais and Vietnamese (I spent several years in these countries) usually don't put the cassava root (tuber) in main dishes... So I am not that familiar with it. As I remember I tried only one dish with cassava: a dessert, boiled cassava tuber (root) with grated coconut.
You can utilize anything from cassava leaves.
Adding fresh cassava leaves to salads possible?