Preheat the oven to 400 degrees. On a lined baking sheet, add red peppers that have been cored, deseeded & sliced into fours. Spray tops with olive oil. Then place in the oven for 35 minutes.
Then you will make the dressing. Add mayonnaise, greek yogurt, lemon juice, garlic, mustard, salt, onion powder & pepper together in bowl. Whisk together.