• 12 small corn tortillas
• Olive oil , for brushing

• 1 can (15 ounces) black beans , drained and rinsed
• 1/4 tsp. ground cumin
• 1/4 tsp. ancho chili powder
• Salt and freshly ground pepper
• 3 ears corn (roasted, sautéed, or raw), kernels only
• 2 bunches cavolo nero , washed and dried, middle stem torn out, and shredded
• 1/2 head (small) red cabbage , shredded
• 5 plum tomatoes , seeded and diced
• 2 avocados , peeled and diced
• 1 bunch cilantro , coarsely chopped
• 1/2 cup cotija cheese , crumbled

• 3 Tbsp. fresh lime juice (about 1 lime)
• 3 Tbsp. coconut vinegar or unseasoned rice vinegar
• 1 medium shallot , finely chopped (about 2 Tbsp.)
• 1/4 tsp. minced garlic
• 1 tsp. salt
• 1 tsp. sugar
• 2 Tbsp. chopped cilantro
• 1 tsp. ground cumin
• 3/4 cup canola oil

• 1 1/2 pounds medium shrimp (about 24), peeled, deveined, and halved lengthwise
• Zest of 1 lime
• 1/4 tsp. salt
• 1/4 tsp. ancho chili powder
• 2 Tbsp. olive oil
• 1/2 serrano chili , minced (optional)

Note: Cavolo nero is a dark green kale from Tuscany; if unavailable, substitute another variety of kale.

To make shells: Preheat oven to 350°. Brush tortillas on both sides with olive oil, and arrange on a baking sheet. Cook 15 to 20 minutes, or until golden and crispy. Let cool in pan; set aside.

To make salad: Put black beans in a large bowl; mix in cumin and ancho chili powder. Season to taste with salt and pepper. Add remaining salad ingredients; toss lightly to combine. Put salad in refrigerator until ready to serve.

To make vinaigrette: In a medium bowl, whisk together lime juice, vinegar, shallot, garlic, salt, and sugar. Let sit for 10 minutes to dissolve salt and sugar. Add cilantro and cumin, then slowly whisk in oil. Set aside.

To make shrimp: Season shrimp all over with zest, salt, ancho chili powder, olive oil, and serrano chili (if using). Grill or sauté in a large skillet in batches over high heat, 1 to 2 minutes per side (until flesh is opaque); remove from heat.

To assemble tostadas: Toss salad, shrimp, and vinaigrette together. Place baked tortilla shells on a large platter, and add a handful of mixture to each; serve.