If using wooden skewers, soak them in water. In a large bowl, mix all the marinade ingredients: olive oil, vinegar, paprika, cayenne pepper, garlic powder, onion powder, salt, and pepper.
Add the diced meat and mix thoroughly. Cover the bowl and refrigerate to marinate for a minimum of 2 hours, ideally 4 hours or overnight.
Thread the marinated meat, onion, and pepper alternately onto the skewers. Try to space the pieces evenly on the skewer and avoid cramming them too tightly.
Preheat the grill to medium-high heat (or a pan with a little oil).
Grill the Brochettes for 10 to 15 minutes, turning them regularly until the meat is browned and cooked to your liking. The internal temperature for medium-rare beef is approximately 60 °C (140 °F).
Serve hot, traditionally with sliced raw onion, which adds a fresh sharpness to the dish.