Dissipative solitons formed in Kerr microresonators may enable chip-scale frequency combs for precision optical metrology. Here, we explore the creation of an octave-spanning, 15-GHz repetition-rate microcomb suitable for both self-referencing and optical-frequency comparisons across the near infrared. This is achieved through a simple and reliable approach to deterministically generate, and subsequently frequency stabilize, soliton pulse trains in a silica-disk resonator. Efficient silicon-nitride waveguides provide a supercontinuum spanning 700 to 2100 nm, enabling both offset-frequency stabilization and optical-frequency measurements with per mode. We demonstrate the stabilized comb by performing a microcomb-mediated comparison of two ultrastable optical-reference cavities.