From East Finchley
Lovely quiet lanes in the summer, but can be a bit gnarly in the winter after rain.
Coffee stop in Hertford or High Barnet
https://www.strava.com/routes/3153317483964902626/export_gpx
Good in winter, maybe but not the prettiest of routes around Welwyn.
Good midway coffee stop at Brewhouse Cafe, Wheathampstead:
https://www.strava.com/routes/3188223454724768466/export_gpx