In qtcreator can I open a non-CMake project?

Question

I like qtcreator. I need to work on a GNU-make-based project. It's a bit weird C++ project where most build rules look like

mos build directory-name

Can I use qtcreator with only the filesystem representation of the project? Or do I need to write down a very simple CMakeLists.txt? Can you give me an example of one that simply recursively lists all subdirectories?

_{For anyone deciding to go the recursive way, this question helps a lot.}