To a large mixing bowl, add the mayo, yogurt, mustard, and ranch. Stir everything together until evenly incorporated.
1/4 cup mayonnaise, 1/4 cup plain Greek yogurt, 1 tbsp Dijon mustard, 2 tbsp dry ranch seasoning
Add in the chicken, bacon, and onions. Toss until everything's coated and evenly incorporated.
1 1/2-2 cups chopped rotisserie chicken, 1/3 cup crisp cooked bacon, 2 tbsp thinly sliced green onions
Refrigerate 1-2 hours, or up to overnight.
Use a small paring knife and carefully slice off the top of each tomato. Use the paring knife to hollow out the tomato, remove the seeds and excess pulp. Be careful not to pierce through the skin of the tomato.
6 large vine-ripened tomatoes
Stuff the tomatoes with the chicken salad until it's all gone. Serve immediately.