Beef Kebabs

Cut the beef into 1.5-inch uniform cubes for even cooking. In a large mixing bowl, whisk together olive oil, soy sauce, Worcestershire sauce, brown sugar, minced garlic, rosemary, thyme, smoked paprika, salt, pepper, and onion powder to create the marinade. Add the beef cubes and toss to coat evenly. Let marinate for at least 15 minutes while you prepare the vegetables. Cut bell peppers and red onion into 1-inch chunks, and prepare mushrooms by leaving small ones whole or halving larger ones. If using wooden skewers, soak them in water for 15-20 minutes to prevent burning.

Thread the marinated beef and vegetables onto skewers, alternating between beef, bell pepper, onion, and mushroom for colorful presentation. Leave small spaces between pieces to ensure even cooking. You should have about 6-8 kebabs depending on skewer size. Reserve any leftover marinade for basting. Preheat your grill or grill pan to medium-high heat. If using an indoor grill pan, ensure it's well-heated and lightly oiled. In a small saucepan, melt butter with chopped parsley to create an herb butter for finishing.

Place kebabs on the preheated grill and cook for 12-15 minutes total, turning every 3-4 minutes to ensure even browning on all sides. Baste with reserved marinade during cooking for extra flavor and to prevent drying out. The beef should develop a nice char on the outside while remaining tender inside. Test doneness by cutting into a piece of beef - it should be cooked to your preference (medium-rare to medium is ideal for tenderness). In the last minute of cooking, brush kebabs with the melted herb butter. Remove from grill and let rest for 2-3 minutes before serving.