Step 1

Place Marinade ingredients in food processor or blender container. Cover; process until almost smooth. Cover and refrigerate 3/4 cup for dressing; cover and refrigerate. Place beef steak and remaining marinade in food-safe plastic bag; turn steak to coat. Close bag securely and marinate in refrigerator 6 hours or as long as overnight, turning occasionally.

Step 2

Combine Slaw ingredients and reserved 3/4 cup marinade in large bowl; toss to coat. Season with salt, as desired. Cover and refrigerate until ready to serve.

Step 3

Prepare Pupusas. Combine corn masa, 1-1/2 cups water, salt and pepper in large bowl until soft dough forms. Gradually add more water, if necessary. Divide dough into 6 equal balls. Make indentation in center of each ball; fill with about 2-1/2 tablespoons cheese. Push dough up and around cheese to completely enclose. Flatten balls with hands or rolling pin into  6-inch discs, making sure dough stays sealed. Cover with damp paper towels until ready to cook. Spray large skillet or griddle with nonstick cooking spray; heat over medium-high heat until hot. Place pupusas in skillet in batches; cook 2 to 4 minutes or until lightly browned, turning once. Keep warm.

Step 4

Meanwhile, remove steak from marinade; discard marinade. Place steak on rack of broiler pan so surface of beef is 2 to 3 inches from heat. Broil 13 to 18 minutes for medium rare (145°F) to medium (160°F) doneness, turning once. Remove; let stand 5 to 10 minutes. Carve steak across the grain into thin slices. Season with salt, as desired.

Step 5

Place 1 pupusa on each serving plate. Top with slaw and beef. Garnish with cilantro, if desired.