A ketogenic diet is a high fat (75-95%), moderate protein (10-15%), low carbohydrate diet (0-5%). The ratios are important, and for weight loss, it is best to keep the carbohydrates less than 50 grams per day. For someone who is insulin resistant, they may need to drop their ketones to 25 grams per day.
Programs like Fit Day and My Fitness Pal are great tracking tools to track your ratios and grams of carbohydrates. Here is an example of what one day on a ketogenic diet looks like.
I hope the example is helpful for you to figure out how to plan a ketogenic diet meal.