Whisk together the olive oil, red wine vinegar, lemon juice, Dijon mustard, garlic, oregano, salt, pepper, and smoked paprika until well combined.
Measure ¼ cup of the marinade into a separate bowl or zip-top bag. Set the remaining mixture aside to use as the salad dressing.
Add the cubed steak to the ¼ cup of marinade. Toss to coat and refrigerate for 30 minutes.
Meanwhile, if using wooden skewers, soak them in water for 20 minutes.
Preheat the grill to high. Thread the marinated steak onto the skewers.
Grill the steak kabobs for 6-7 minutes, turning every minute or two so they cook evenly on all sides. Cook until the steak reaches your desired doneness.
Remove the kabobs from the grill and let them rest for a few minutes.
Steak Salad
Arrange the chopped romaine lettuce on a large serving platter.
Top with the grape tomatoes, sliced cucumber, red onion, feta cheese, and stuffed grape leaves.
Drizzle the reserved marinade/dressing over the salad as desired.