OP, I agree with you on the simplicity aspect. But do variety, too. Vary your veggies. I'd alternate between chicken and fish, (Tuna fish is fine.) Eat salads using olive oil and balsamic.
If you grill veggies in the oven (400 degrees for about 25 minutes)use Olive oil & balsamic to flavor them. Don't be afraid of seasonings. Some garlic powder, crushed red pepper...and olive oil make green beans and Brussels sprouts delish after you steam them.
All these things are quick too. If you have a microwave, just wash you Brussels sprouts, or broccoli, or green beans, put them in a bowl with about an inch or two of water, and cook them for about 4-6 minutes.
Stick a fork into them to see if they're tender enough, drain off the water, drizzle olive oil and seasonings, and sort of mix to make sure the seasoning and the drizzle of oil (No more than a table spoon) coats the veggies evenly. There. You're ready to eat. If you grill a chicken breast seasoned well, and cooked in a toaster oven for about 30 minutes, you have a meal.
What's important is to eat often. Like every three hours. But eat sparingly. A piece of smoked turkey or ham wrapped around a stalk of celery, or a hard-boiled egg or a tossed salad with just a drizzle of dressing will do. Remember.
Veggies and salads are "free." As long as you're careful with the dressing and oil and use them sparingly, and compensate with other seasonings, you can eat a lot of veggies and not ruin your diet. Fruit will put weight on you so be very careful. No bananas. Eat an orange or some grapefruit. No more than one apple a day.
Always eat breakfast. Oatmeal, or yogurt, or cottage cheese with fruit. Try to limit your bread to a high fiber whole grain bread and eat only one slice a day if you must. It would be better to try not to eat any at all.
Stop using butter or margarine. Use Olive oil. Olive oil is my favorite thing in the world and it's healthy for you. Go to Trader Joe's and get some good olive oil at a good price.
Don't drink anything carbonated or artificially sweetened. Drink Iced tea with honey in it, and drink water. No fruit juices either. None. No orange, apple or grape juice. too much sugar, too many calories. Empty calories.
Good luck to you. I'm certain that if you stick to your diet, and remember to eat several times a day, to keep your metabolism from slowing down, you will realize weight loss that is noticeable in less than a month.