In a big pot, add 3 tablespoons of vegetable oil and ⅓ cup popcorn corn kernels. Cook on medium-low until you hear the first pop. Move the pot around and continue cooking until you stop hearing kernels pop. Remove from heat and set aside.
In a medium-sized skillet, cook the bacon and drain it on paper towels. Crumble when cool and reserve a little for the topping.
In a large salad bowl, mix the mayo, yogurt, red wine vinegar, celery, carrots, water chestnuts, ¾ cup of shredded Cheddar, and crumbled bacon (reserve a little bit for topping). Mix until well combined.
When ready to serve, mix in the popcorn
Top with reserved bacon, ¼ cup reserved Cheddar cheese, and chives