Spicy Beef Gyros with Tzatziki Sauce

Ingredients

• 2 tablespoons beef bouillon granules
• 2 tablespoons water
• 3 cloves garlic, minced
• 2 teaspoons cayenne pepper
• 1/2 teaspoon salt
• 1 teaspoon black pepper
• 1 1/2 pounds beef sirloin, cut into 1/2-inch cubes
• 10 wooden skewers, soaked in water for 1 hour
• 2 tablespoons vegetable oil
Greek Tzatziki Sauce
• 1 (32 ounce) container plain Greek yogurt
• 1/2 English cucumber with peel, grated
• 1 clove garlic, pressed
• 2 tablespoons fresh lemon juice
• 2 tablespoons extra-virgin olive oil
• 2 teaspoons grated lemon zest
• 3 tablespoons chopped fresh dill
• 2 Tbsp. chopped fresh mint
• 1/2 tablespoon salt
• 1/2 tablespoon fresh ground black pepper