They say breakfast is the most important meal of the deal and while in theory that may be true I modify it to say your FIRST meal of the day is the most important, whenever that may occur.
I am a huge fan of Bulletproof Coffee as a tool to be used when needed. When I wake up at 4AM there's nothing easier then pouring some MCT Oil, a thick slice of butter, and some upgraded coffee into a mug before whirring it up with a 99 cent IKEA milk frother. I can go from zombie to sharp as a tack in about 4 minutes. There are several benefits to starting the day with a huge boost of fat. First, it's easy, second it's satisfying, and third, the lack of carbs or protein means I'm not setting up my body's clock to think that 4AM is the true start of the metabolic day, meaning I would be craving a meal around 3pm and crashing shortly thereafter. With one cup off butter coffee I can go until at least noon without the slightest urges of hunger.
However, when I do have the time to eat a little more than I like to eat 4 lightly poached eggs (healthiest way to eat an egg as you avoid oxidizing any of the fats) with a little bit of cheese, some grass fed butter, a sprinkle of pink himalayan sea salt, and a whole sliced avocado. Fat, fat, and some fat, yum! Here's the easiest way to make perfect poached eggs. Get yourself some Poach Pods, put a couple inches of water in a pot and let it boil. Put a little olive oil in the poach pods, drop in the eggs, sprinkle in the sea salt, and put the pods in the water. Cover them up and set a time for 4 minutes. Remove and enjoy.