Preheat the Oven and Prepare the Baking Sheet:

Preheat your oven to 425°F (220°C). Line a large baking sheet with parchment paper.

Season the Asparagus and Shrimp:

In a large bowl, combine the asparagus with 1 tablespoon of olive oil, salt, pepper, and half the smoked paprika and onion powder. Spread on one half of the baking sheet.

In the same bowl, toss the shrimp with the remaining olive oil, smoked paprika, cayenne pepper, onion powder, salt, and pepper. Arrange the shrimp on the other half of the baking sheet in a single layer.

Roast:

Roast in the preheated oven for about 12-15 minutes, or until the shrimp are pink and cooked through and the asparagus is tender.

Make the Spicy Lemon Garlic Sauce:

While the shrimp and asparagus are roasting, melt butter in a small saucepan over medium heat. Add the minced garlic and cook until fragrant, about 1 minute.

Stir in the lemon zest, lemon juice, parsley, cilantro, and red chili flakes. Season with salt and pepper. Cook for another 2 minutes, stirring frequently.

Combine and Serve:

Once the shrimp and asparagus are done, remove from the oven. Pour the spicy lemon garlic sauce over the shrimp and asparagus, tossing gently to coat evenly.

Garnish with lemon slices, additional parsley, and cilantro.

Enjoy:

Serve hot, with extra lemon slices on the side for added zest.