01 - Whisk together olive oil, lemon juice, smoked paprika, garlic powder, onion powder, salt, and pepper in a large bowl until well combined.
02 - Add steak cubes and shrimp to the marinade. Toss until evenly coated. Cover and refrigerate for 15-30 minutes.
03 - Heat grill to medium-high (425°F). Soak wooden skewers in water for at least 20 minutes if using.
04 - Thread steak and shrimp alternately onto skewers, spacing pieces evenly for uniform cooking.
05 - Place skewers on grill and cook for 6-8 minutes, turning occasionally, until steak reaches medium-rare and shrimp are opaque and pink.
06 - Melt butter in small saucepan over medium heat. Add garlic and cook 1-2 minutes until fragrant. Stir in parsley, lemon juice, salt, and pepper. Remove from heat.
07 - Remove skewers from grill and drizzle immediately with warm garlic butter sauce. Garnish with parsley and serve with lemon wedges.