Soak wooden skewers in water for 30 minutes to prevent burning on the grill.
In a large mixing bowl, combine 1.5 lb ground beef, 0.5 cup grated yellow onion, 3 tbsp chopped fresh parsley, 1 tbsp chopped fresh mint, 3 cloves minced garlic, 1.5 tsp kosher salt, 1 tsp ground cumin, 1 tsp ground coriander, 0.5 tsp black pepper, and 0.5 tsp ground cinnamon. Mix gently by hand until just combined.
Divide the seasoned beef mixture into 8 equal portions. Form each portion into a long, oval cylinder around a soaked wooden skewer.
Preheat the grill to medium-high heat (around 375°F to 400°F) and lightly oil the grates.
Grill the beef skewers for 8 to 10 minutes, turning occasionally, until nicely charred and the internal temperature reaches 160°F.
Remove from the grill and let rest for 3 minutes. Serve warm with 1 cup tzatziki sauce, 1 cup hummus, 2 cups sliced cucumbers, and 2 cups diced tomatoes.