Just thought I'd contribute since I didn't see these up here. Some of my favorite eats when I used to live in Santa Monica and rode the canyons daily...These are just a few that I've been to (and have gone back to)...
Malibu Seafood - just north of Malibu Canyon Road (Pepperdine); the perfect lunch spot after your Mulholland Raceway jaunts...GREAT food!! (I'm jonesin' for an Ahi Tuna Burger!)
Nobu Malibu - if you're a sushi connoisseur, there's hardly a place better in Los Angeles...pricey but hey, maybe you'll see a celebrity (I sat at the table next to the Olsen twins on their 18th birthdays)
Reel Inn - pretty good, kinda expensive, but conveniently close to Santa Monica (near Topanga Canyon). The link on Citysearch says there's another location at the 3rd Street Promenade. They CLOSED that location months ago...
Duke's - kick ass Sunday brunch, AWESOME views, right across from Las Flores Canyon Rd (a fun, short, uphill twisty that leads to the Piuma-Schueren-Stunt loop that is off of Mulholland)
others you may wanna try include...
Moonshadows - great views
Gladstone's - food is just ok, convenient to Santa Monica, at intersection of Sunset Blvd. and PCH
Patrick's Roadhouse - never been there, heard it was cool
etc., etc....spend some time on Citysearch site to find exactly what you're looking for.