Make the tortilla bowls: Position a rack in the lower third of the oven; preheat to 450 degrees F. Put 4 empty cans (labels removed) or small ovenproof bowls upside down on a baking sheet. Drape a square of foil over each can and coat with cooking spray.

Fill a shallow bowl with ½ inch warm water; whisk in the olive oil. Soak each tortilla in the water until soft, about 5 seconds, then drape over the prepared cans, pleating as needed. Bake until golden, about 5 minutes. Remove from the oven and invert the tortilla bowls onto the baking sheet; remove the cans and foil. Spray the inside of the tortilla bowls with cooking spray, season with salt and continue baking until crisp, 4 to 5 more minutes; let cool.

Meanwhile, make the steak: Whisk the dried garlic, onion and oregano, the cumin, chile powder, scallions, Worcestershire sauce, olive oil, 1 ½ teaspoons salt and 1 teaspoon pepper in a bowl. Put the steak in a shallow dish and rub with 2 tablespoons of the spice mixture (reserve the rest for the dressing). Add the bell pepper and sliced onion and toss. Cover and refrigerate 30 minutes or up to 4 hours.

Heat a large cast-iron skillet over high heat. Add the steak and scatter the bell pepper and onion around it. Sear the steak about 5 minutes per side, then transfer to a cutting board. Continue cooking the pepper and onion until just tender, about 3 more minutes. Thinly slice the steak against the grain, then cut into 1-inch pieces.

Assemble the salad: Whisk the mayonnaise, buttermilk and the reserved spice mixture in a large bowl until smooth. Add the cucumber, lettuce, beans and olives and toss. Divide the salad among the tortilla bowls. Top with the steak, bell pepper, onion, cheese and salsa.