Preheat oven to 425°F (220°C).
In large bowl, combine all meatball ingredients except olive oil. Mix gently with hands.
Form into 1.5-inch meatballs (about 24 total) using a cookie scoop.
Place on oiled baking sheet and bake 15-20 minutes until internal temperature reaches 165°F (74°C).
For tzatziki: Pulse cucumber, garlic and dill in food processor. Mix with yogurt, lemon juice and salt.
Serve meatballs warm with tzatziki sauce.