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This is the true ultimate breakfast sandwich, fully loaded with soft scrambled eggs, juicy sausage, caramelized onions, melted cheddar, and creamy avocado. All good things are wrapped up in one to give the best bite!


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What makes this dish special
I am a lover of all breakfast foods. Sweet, savory, healthy, or hearty, I have no judgment. The more I've grown to love eating breakfast sandwiches, the more I've noticed how difficult it is to find a restaurant that can make a decent one. I blame myself since I'm a professional chef and tend to have high standards. Even the popular "Eggslut" in Los Angeles did not meet my expectations.
Once I bit into that sausage and soft scrambled egg on brioche, I was content, but not to my satisfaction. I knew that I could make my own version with some extra toppings and save myself that hour's wait. So, here is my ultimate breakfast sandwich with soft scrambled eggs, sausage, caramelized onions, cheddar, and avocado.
This breakfast sandwich takes a little more time than the typical sausage and egg on a muffin, but with good reason. Several elements make this the ultimate breakfast sandwich, including the caramelized onions, spicy aioli, creamy avocado, and soft scrambled eggs. All of these ingredients work together to bring about an explosion of flavors.
For more breakfast sandwich ideas, check out this chicken sausage breakfast sandwich, Taiwanese sausage McMuffin, and breakfast croissant sandwich bake!
Recipe
The Ultimate Breakfast Sandwich
Ingredients
Spicy aioli
- 1 tablespoon mayo
- 1 teaspoon sriracha
Sandwich
- 2 tablespoons oil, divided
- ½ onion thinly sliced
- 2 breakfast sausage patties
- 2 slices hard cheddar
- 3 large eggs
- 1 tablespoon chives chopped
- ½ avocado sliced
- 2 brioche buns toasted
Instructions
- Make the sriracha aioli. Mix the mayo and sriracha in a small bowl and set aside.
- Heat 1 tablespoon oil in a nonstick pan over medium-high heat. Add the sliced onion and saute until softened, about 5 minutes. Reduce heat to medium-low and continue to cook until caramelized, about 20 minutes.
- Meanwhile, heat another pan over medium heat. Cook sausage patties until almost done. Lay 1 slice cheddar per patty and cover for 45 seconds or until cheese has melted. Set aside and keep warm.
- Prepare the scrambled eggs. Whisk together the eggs with the chives in a bowl. Heat 1 tablespoon oil in a nonstick pan over medium heat. When the pan is hot, add the eggs. Let it stand for 30-60 seconds, just long enough to set around the edges. Use a spatula and fold the eggs, lifting and folding the eggs to cook. Do not stir vigorously or whisk - you want the creamy texture which is achieved through the folding. Season with salt and pepper and remove from heat.
- Assemble the sandwiches. Spread spicy aioli on the bread and top with the sausage, eggs, caramelized onions, and avocado. Serve immediately.
Notes
Step-by-step instructions
Step 1: Caramelize onions
Start by making the caramelized onions. Thinly slice half of a yellow onion. I prefer using yellow onions because they have a high sugar content and a strong flavor. You can use sweet onions such as Vidalia, but they might not caramelize as deeply.
Heat oil in a large saute pan and add the onions. Saute the onions until softened over medium-high heat, then reduce the heat and continue to cook until deeply browned, stirring occasionally.

Properly caramelized onions can take up to 40 minutes. Since we're only cooking ½ an onion, the cooking time is shorter, about 20 minutes. If the pan gets too dry, add a splash of water.
Since the onions take the longest to prepare, you can cook them ahead of time and reheat them right before assembling the sandwiches.
Step 2: Prepare sausage
For the sausage, purchase the breakfast sausage in bulk rather than the pre-shaped patties. This allows you to make your own size patty according to the size of your bun; I found that the pre-sized ones are just too small. Keep in mind that the sausage does shrink quite a bit when cooking.
You can also buy ground pork, turkey, or chicken and season the patties to your liking.

Although I cooked the sausage patties on the stovetop, you can cook them in the oven as well. Once cooked, place a slice of cheese on top and warm until the cheese melts.
Step 3: Cook eggs
Now the eggs. Cooking scrambled eggs is easy, but cooking soft scrambled eggs takes a bit more technique. Start by heating oil in a nonstick saute pan over medium heat. You can also use butter for richer eggs.
When the pan is hot, add the eggs. Let it stand for 30-60 seconds, just long enough to set around the edges. Use a spatula and fold the eggs, lifting and folding them to cook. Do not stir vigorously or whisk - you want the creamy texture, which is achieved through the folding.

I remember the first time I learned how to make proper scrambled eggs at the Culinary Institute of America. I thought the eggs were underdone because I wasn't used to having them taste, well, rubbery. It was then that I learned that I was waiting too long before taking the eggs off the pan.
Eggs will continue to cook even after you turn off the heat, so it's important to take them off when they look slightly underdone.
Also, make sure to season after the eggs are cooked. Salting the eggs beforehand draws out the water, making them drier. Practice makes perfect, so if it doesn't come out right the first time, just keep trying!
Step 4: Assemble sandwiches
Now that all the cooked components are ready, all that's left is to slice an avocado and make the sriracha aioli. The aioli can also be prepared up to 5 days in advance.

Toast the brioche buns, and it's time to put it all together. Top the bottom bun with a good smear of the spicy aioli, followed by the sausage patty, eggs, caramelized onions, and avocado. Place the remaining bun on top and dig in immediately. This sandwich waits for no one!
I can say without a doubt that this breakfast sandwich is better than many others I've bought. There are so many different components that work beautifully together, from the creamy eggs to the salty sausage to the sweet onions. And the plus side? Not having to wait for an hour!
For another fun breakfast idea, check out this egg salad avocado toast with jalapeno pesto!

Make-ahead and storage
- Make-ahead: You can prepare the spicy aioli and caramelized onions ahead of time and store them in the refrigerator. Simply reheat the caramelized onions before assembling the sandwiches. The sausage can also be cooked ahead of time and kept warm in the oven at 225 degrees F.
- Store: Keep all of the components in separate containers in the refridgerator. The spicy aioli will hold for up to 5 days, while the caramelized onions will keep for 3 days.
More breakfast sandwich recipes
Looking for more breakfast sandwich ideas? Try these:

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All images shot and styled by Christine Ma. Available for food photography, styling, and recipe development.











Mary @ LOVE the secret ingredient says
My goodness! I wouldn't normally order a sandwich like this, but I have to admit your recipe looks delicious! And thank you for the tips, I'll have to share this recipe with my sons 🙂
cma0425 says
Thanks for visiting!
Elsa says
What kind of pork are you buying for the sausage patties? Do you put anything else in to make the patty? This recipe looks like something my grandkids would devour
Cherry on My Sundae says
I actually just bought the seasoned breakfast sausage at the market and used them for the patties - didn't add anything to them. The premade breakfast sausage at the market is already heavily seasoned so just shape them into patties and cook! Let me know if you have any other questions.
Jessica says
Sounds delicious! Can the sandwich be prepared ahead of time and reheated?
Cherry on My Sundae says
Technically, yes it can but it's best when fresh. I would recommend making the spicy aioli and caramelized onions, and cooking the sausage patties ahead of time. Then when you're ready to eat, you can cook the eggs and reheat the sausage patties with cheese and assemble the sandwiches.