This is some variety of Choisya in the Rue Family (Rutaceae). The genus is native to Arizona, New Mexico, Texas, and northern Mexico.
I wish I could see the details of the plant more clearly. It looks like the lens had begun to fog when this pic was taken.
Most likely it is a cultivar of Choisya x dewitteana, which is a hybrid of C. arizonica and C. ternata. There are two commonly sold cultivars of this cross: 'Aztec Pearl' and 'Londaz', the latter is often sold under the trade name of White Dazzler™.
Another possibility is that this is a selection of Choisya arizonica, C. dumosa, or C. mollis.
(N.B. Some taxonomists treat all three of these species as varietas of C. dumosa).
There are additional cultivars and hybrids with these species, including C. arizonica 'Bluestone', introduced by Portland's Cistus Nursery.and several more hybrid cultivars introduced by plant breeder, Peter Moore, including some with lutescent foliage.