2 limes
2 scallions
1 package (10 ounces) frozen corn kernels
3 tablespoons olive oil
Coarse salt and ground pepper
1 jalapeno chile
1 pint grape tomatoes
8 ounces Monterey Jack cheese, not sliced
4 flour tortillas (6-inch)
1 can (15 ounces) black beans
1 avocado
Reduced-fat sour cream, for serving (optional)
IN THE MORNING
1. Start corn relish: Squeeze limes into a medium bowl. Thinly slice scallions, and add to bowl along with corn. Add 1 tablespoon oil, and season with salt and pepper; toss to combine. Cover and refrigerate.
2. Prep vegetables: Halve jalapeno (remove ribs and seeds for less heat, if desired), and mince. Halve tomatoes. Combine in an airtight container; cover and refrigerate.
3. Shred Cheese: Coarsely grate cheese on a box grater; place into a resealable plastic bag, and refrigerate.
AT DINNERTIME
1. Make tostadas: Preheat oven to 475 degrees. Arrange tortillas on two baking sheets; brush both sides with remaining 2 tablespoons oil. Rinse and drain beans; sprinkle over tortillas. Top with tomatoes, jalapeno, and cheese. Bake until golden and crisp, about 10 minutes, rotating sheets halfway through.
2. Finish corn relish: While tostadas are baking, pit and peel avocado; dice. Toss with corn mixture to combine.
3. Serve: Top tostadas with corn relish, and, if desired, sour cream.