Place 20 oz potatoes in a bowl covered in plastic wrapper. Microwave for 7 minutes.
Meanwhile, marinate 15 oz shrimp with 1/4 tsp salt, 1/2 tsp black pepper, 1 tsp paprika, 1/2 tsp oregano, 1/4 tsp cumin, 1/4 tsp chili powder, 1 tsp garlic powder, 1/2 tsp cayenne, 1/2 tsp brown sugar, 1 tsp garlic, and 1 tsp lime juice. Set aside.
Fill a large skillet with 1 - 2 inches of water. Bring the water to a boil over high heat. Add 16 oz asparagus and cook for 2 minutes. Risen the cooked asparagus briefly with cold water and transfer them to a serving dish.
Heat a skillet over medium heat. Add 2 tbsp olive oil and the marinated shrimp to the preheated skillet. Cook the shrimp until pink and opaque on one side and flip to the other side. The shrimp will take 10 - 12 minutes to cook all together.
Take the potato bowl out of the microwave. Add 3 1/2 tbsp butter, 1/4 tsp salt, and 2 tbsp parsley. Use a large fork to mash the potatoes to your desired consistency.
Garnish the seared shrimp with 2 tbsp chopped coriander. Serve the blackened shrimp with mashed potatoes and asparagus.