Hi Hans,
I will write what I want to acomplish. While it is definitely thrivial, I'm either missing something obvious or more experienced users suffer from the curse of knowledge.

I want ot use Roboto Flex for my chapter and section heads with Garamond Premier for the body contents.

I followed the Context wiki example and consistant examples from the web.

Here is my code:
\usemodule[fonts-variable]
\definefontfamily[roboto-flex][ss][rotoboflex]
% robotoflex.ttf is the recognized font file name.
\setuphead[chapter]
[style={\switchtobodyfont[roboto-flex,20pt]\ss}]

While the Garamond is embedded and text is styled, the chapter tible is typeset with Garamond not Roboto.

Any hints or feed back will be very appriciated.

Thank you,
Pawel