Greek Meatball Appetizers

Ingredients
To make the tzatzitki sauce;
½ cup grated cucumber squeezed dry
½ cup finely diced red onions
2 cups plain Greek yogurt
1 teaspoon dried oregano
1 teaspoon fresh lemon zest
⅛ teaspoon black pepper
¼ teaspoon coarse salt
½ teaspoon garlic powder
To make the Greek meatball appetizers;
2 pounds ground lamb
½ cup breadcrumbs
8 ounces frozen spinach thawed and squeezed dry
2 teaspoons fresh lemon zest
2 teaspoons dried oregano
½ cup crumbled feta cheese
2 teaspoons garlic powder
2 teaspoons coarse salt
1 teaspoon black pepper
2 tablespoons olive oil

Preparation
To make the tzatziki sauce;
Place all of the sauce ingredients in a medium bowl and stir well to combine.
Cover and keep refrigerated until ready to serve.
This can be made up to 5 days in advance.
Do not freeze
To make the Greek meatball appetizers;
Preheat oven to 350-degrees.
Place all of the meatball ingredients (except olive oil) in a large bowl and mix until thoroughly combined.
Shape into 1" round side meatballs.
Add the oil to a large skillet.
Brown the meatballs (working in batches) on all sides.
Remove the browned meatballs and place them on a baking sheet.
Bake the browned meatballs in the preheated oven for 10 minutes.
Remove the meatballs from the oven and serve them in a bowl with appetizer picks and the chilled tzatziki sauce.