One of my go to make ahead breakfasts is an egg bake, and today I want to share one of my favorites with you. It’s so incredibly easy to make that even the cooking challenged can handle it.

Tomato, Mushroom, and Onion Egg Bake 

Serves 6-8


  • 9 large, organic, cage-free eggs
  • 1/4 cup milk of choice
  • 1-2 tbsp extra virgin olive oil
  • 10 ounces mushrooms, sliced
  • Half a yellow onion, sliced
  • 3 plum tomatoes, diced and salted
  • Salt and pepper, to taste
  • Cheese of choice, optional
  • 3 dashes hot sauce, optional


  1. Preheat your oven to 350 degrees F.
  2. In a large bowl, whisk together the eggs, milk, pepper, and hot sauce (if using).
  3. Heat the extra virgin olive oil over medium heat in a skillet. Add the sliced onions and a pinch of salt, and cook until the onions become translucent, about 5-7 minutes. Add the sliced mushrooms, and cook for another 4-5 minutes.
  4. Spray an 8×8 baking dish with cooking spray. Spread the mushrooms and onions around the bottom of the dish first. Then pour the egg liquid mixture on top and spread evenly. Finally, top with the diced tomato and cheese (if using).
  5. Cook for 35 minutes or until the top of the egg bake is set. A good test is to wiggle the pan! If the middle of the egg bake is jiggly at all, then cook for longer.

Tomato, Mushroom, and Onion Egg Bake

I like making egg bakes at the beginning of the week so that I have a hassle free breakfast ready to go for busy weekday mornings. Before heading to the gym for early morning workouts, classes, or clients, I’ll typically eat something small on the way out the door such as a banana, grain free muffin, energy ball, or Ezekial toast/waffle with nut butter. However, I’ll bring a piece of this egg bake with me for something more satisfying to heat up and eat later on as I’m between classes and clients. It’s perfect for post workout fuel, it’s full of protein, and it keeps me going through the morning.

Tomato, Mushroom, and Onion Egg Bake

Another reason I love making egg bakes is because there are so many different versions you can play with. You can basically use whatever veggies you have in your fridge and still follow this recipe format! Even though I love this tomato, mushroom, and onion version, we tend to change things up week to week so we don’t get bored. Some of my other favorite flavor combos include spinach, mushroom, and feta or broccoli and red pepper. Many times I’ll add a scoop of guacamole on top or sliced avocados. Sometimes we’ll cook up the veggies first, sometimes we’ll just chop them. Sometimes we add cheese, but many times we’ll leave it out to limit dairy. It just depends on what you feel like!

Tim really likes adding breakfast meats to the egg bakes, which we’ll also do sometimes with a nitrate/nitrite free breakfast sausage or bacon. If you add meat, I would suggest cooking it before you prep any of the veggies, and then if you are sautéing any vegetables you can do it in the meat drippings for extra flavor. I actually prefer the taste of the veggie only egg bake, so this is a point of disagreement in our home. I’d rather just eat my bacon on the side. 🙂

Tomato, Mushroom, and Onion Egg Bake

Let me know if you try this recipe! If you make it, post it on social media with #achieveawesome and tag me @fitnessandfeta.

For other make ahead breakfast ideas, check out: