In traditional preservice teacher education programs, education courses are "add-ons" to science content courses. As a result, future teachers are taught the importance of authentic inquiry and constructivism, but they may never learn science in the way they are expected to teach it. University of California San Diego's California Teach program bridges this divide through genuine sharing of expertise between the faculty of Physical Sciences and the faculty of Education Studies in a new undergraduate program that was developed, approved, and implemented within one year. Lessons learned from the collaborative efforts to design the program have relevance to those at other institutions seeking to bridge the divide between the science and education departments or to develop other interdisciplinary academic programs. The California Teach formula for success includes five key ingredients: (a) mutual benefits, (b) recognition of distinct sets of expertise, (c) agreement on core principles, (d) willingness to negotiate, and (e) strong leadership. In concert with administrative buy-in and advocacy, science education faculty catalyzed collaboration by changing attitudes locally and across departments.