One approach is to talk to consulting/contracting companies. They usually have clients using different technologies. This might give you an opportunity to lead on the tech you're most familiar with (immediate value to the company) and still be able to learn new skills. People with the capacity and desire to pick up new technologies can be valuable in consulting/contracting roles. Also, if you explain what you're looking for in your cover letter, it might help screen for companies that match - avoid wasting time on interviews that won't go further.