Pork Gyros with Tzatziki

Pork

• ½ oz vegetable oil
• 4 oz yellow onions, sliced in half moons (¼ in.)
• 8 oz pork tenderloin, cut into strips (¼ in.)
• 1 tsp spice mixture for gyros, to taste (see Tip)

Tzatziki Sauce

• 1 garlic clove
• 3 ½ oz cucumber, peeled, cored and cut into pieces (1 in.)
• 8 oz plain yogurt
  or 8 oz sour cream
• 1 tsp lemon juice
• 1 sprig fresh dill, plus extra to garnish
• ¼ tsp salt, to taste
• 2 pita breads, warmed
  or 2 flatbreads, warmed
• 1 lemon, in wedges, to garnish