1 teaspoon ground cumin
1/2 teaspoon salt, divided
1 (16-ounce) lean flank steak (3/4- to 1-inch thick)
2 large plum tomatoes, seeded and chopped
1 large avocado, chopped
1 cup chopped English cucumber (about 1/2 a cucumber)
1 small jalapeño, seeded and minced
1/4 cup chopped fresh cilantro
2 tablespoons fresh lime juice
Sprinkle cumin and 1/4 teaspoon salt evenly on all sides of steak. Let stand 10 to 15 minutes or cover and refrigerate several hours.
Preheat grill or grill pan to medium-high heat.
Spray grill grates with cooking spray. Grill steaks 4 to 5 minutes on each side for medium-rare or to until desired degree of doneness. Let rest 5 minutes before slicing.
While steak rests, combine tomatoes, avocado, cucumber, jalapeño, cilantro, lime juice and remaining 1/4 teaspoon salt in a medium bowl. Thinly slice steak and top with salsa.