The interior designer Peter Mikic stands in the kitchen of Keepers Farm, the home in Oxfordshire he shares with his television-producer husband, Sebastian Scott, and their dogs, Trigger and Henry. The space is filling up with lunch guests. A long dining table, hewn from a single piece of wood cut from a London plane tree, is decorated with vases of spring flowers and surrounded by Pierre Jeanneret-style chairs. It is positioned in front of a vast wall of glass, designed to slide open in…

