Pork Souvlaki with Lemon Oregano Tzatziki

Name: Pork Souvlaki with Lemon Oregano Tzatziki
Ingredients: * 2-3 lb pork sirloin or tenderloin; for the souvlaki marinade; * 6 tbsp fresh lemon juice; * 3 tbsp olive oil; * 2 tbsp balsamic vinegar; * 1/2 tsp kosher salt; * 1 tbsp rounded smoked paprika; * 1 tsp freshly ground black pepper; * 3 clove minced garlic; for the lemon oregano tzatziki; * 3 cup greek yogurt drained; * piece of english cucumber; * 1 tsp dried oregano leaf; * 2 clove minced garlic; * 3 tbsp fresh lemon juice; * zest of 1/2 a lemon finely minced (optional); * 2 tbsp olive oil; * pinch salt and pepper to season