My mother always made London Broil with top round and flank steak was stuffed with bread and braised and just yuck! Grilling flank steaks allows it's beefy flavor to shine. This recipes is spicy and sweet.
In a bowl, whisk together the minced chipotles, honey and garlic; whisk in the oil.
Season the steak all over with salt, then massage in the chipotle mixture evenly over the entire steak; let marinate at least 1 hour at room temperature, or up to overnight, refrigerated (bring to room temperature before grilling).
Preheat grill; brush off any bits of garlic or chile from the meat and grill, covered, until the steak is a bit charred on the outside and done to your taste on the inside, 4 to 5 minutes per side for medium-rare.
Let meat rest for 5 minutes or so, before slicing across the grain.