Smashed Potato Salad

Ingredients

• 2 lbs creamer potatoes
• 3 tbsp olive oil
• ½ tsp salt, divided
• ½ tsp black pepper , divided
• 1 tsp garlic powder, divided
• ¾ cup plain 2% Greek yogurt
• 4 tbsp mayonnaise
• 2 tbsp stone ground dijon mustard
• 1 tbsp apple cider vinegar
• 1 tbsp dried dill
• ½ cup cucumber, finely chopped
• ½ cup celery, finely chopped
• 1 shallot, finely chopped
• 1 green onion, finely chopped for sprinkling