No one knows when the triumphant troika of bacon, lettuce and tomato first landed between two slices of bread. One of its earliest records—the 1929 cookbook Seven Hundred Sandwiches—helpfully notes that “sandwiches containing bacon are particularly good on hikes or picnics.” By the ’50s, the BLT had moved well beyond backpacker fare and was a diner staple. Now, in our pork-a-holic age, this humble artery clogger has spawned some grandiose permutations.

Treadwell: Crab BLT, $16
Premium ingredients of local provenance are behind the luxe BLT at Treadwell (61 Lakeport Rd., St. Catharines, 905-934‑9797), a farm-to-table mecca. Chef Stephen Treadwell uses pancetta from Niagara-based Mario Pingue; baby lettuce comes from the nearby Tree and Twig farm, as do heirloom tomatoes bathed in a soy marinade and oven-dried to concentrate the sweetness. It’s all layered on a brioche bun and piled with a mound of mayo-dressed crab and nutty Niagara Gold cheese.

Patrician Grill: BLT, $4.95
“White or brown?” “Mayo?” These are your only BLT options at Patrician Grill (219 King St. E., 416-366-4841), a landmark greasy spoon. The secret is a cast iron bacon press, which flattens the rashers, ensuring crisp perfection. Stacked on buttered toast, the salty bacon is balanced by juicy tomatoes and crunchy lettuce. Great gobs of mayo elevate it to diner divinity. Just don’t try to hold the tomato: special requests will earn a side order of tongue-in-cheek from manager Terry Papas—“You want a BL?!”