I like my london broils in the Montreal Steak Marinade:
1/4 cup canola oil
1/4 cup water
2 Tbsp white vinegar.
1 Tbsp Montreal Steak Seasoning
Whisk together and pour over the top of your meat. This one marinaded about 3 hours. The longer the better. I shoot for 1 hour minimum.
Get your grill good and screaming hot...
Toss on your london broil on the rack. Flip after 10 minutes:
Any scraps? ;)
10 more minutes after the flip. I know that sounds long for beef, but this was a thicker cut than most london broils. You can go by temperature or feel. For something half this thickness, 5 minutes a side for medium would be good.
Let rest 5 minutes, then slice...
Perfect medium. Nice a juicy. The corn wasn't bad for early season as well.