Lunch between the Mouse and the Lego...?
Tons of good restaurants between the two. Unfortunately, most of the route belongs in the LA board and the other bit is in the San Diego Board (Camp Pendleton covers a lot of the route in San Diego) and none of it is now in the California Board.
I'd suggest you decide if you want to eat before or after Camp Pendleton. If before, search LA for Laguna Niguel or San Clemente/San Juan Capistrano...if after, search San Diego for Oceanside or Carlsbad.