We’re in the midst of the most in-between of seasons, when winter and spring overlap and a few tantalising but preemptive glimpses of summer get thrown in. So where to spend the brighter days and ever-so-slightly longer evenings? Swap your heavy coat for a lighter jacket (and have both an umbrella and sunglasses to hand) and head for London’s loveliest indoor/outdoor destinations for all-weather alfresco dining.