In a large bowl, combine the cubed sirloin steak with olive oil, smoked paprika, garlic powder, and seasoning with salt and pepper. Mix well and let it marinate for at least 30 minutes.

In another bowl, toss the peeled and deveined shrimp with olive oil, salt, and pepper. Set aside.

In a small saucepan, melt the unsalted butter over low heat. Add the minced garlic and cook for 1-2 minutes until fragrant. Remove from heat and stir in the parsley, lemon juice, and a pinch of salt.

Thread the marinated steak and shrimp onto skewers, alternating between the two. If using wooden skewers, soak them in water for 30 minutes beforehand to avoid burning.

Preheat the grill to medium-high heat.

Grill the skewers for about 3-4 minutes on each side, until the steak reaches your desired doneness and the shrimp are pink and opaque.

Remove the skewers from the grill and drizzle the garlic butter sauce over the top before serving.