Hi @SandervandenOord! Welcome to the Streamlit community! 
I believe the incantation you’re looking for is:
st.bokeh_chart(hv.render(nice_plot, backend='bokeh'))
Also, since hv.render(..., backend='bokeh') has type bokeh.plotting.figure.Figure, you could also just use:
st.write(hv.render(nice_plot, backend='bokeh'))
Please let us know if you have further questions!