For the shrimp: Toss shrimp with canola oil, lime juice, chili powder, cumin, salt and pepper. Marinate shrimp for 10 minutes. Preheat grill pan to medium-high heat. Grill shrimp for 4-5 minutes total, flipping once halfway through.
To assemble tostadas: Top each corn tortilla shell with shrimp, cabbage, radishes, avocado, onions and tomatoes. Drizzle with Marie’s Creamy Avocado Poblano Dressing. Garnish with cilantro. Serve with lime wedges and hot sauce.