The Best Vegetarian Keto Burger

This really is the best vegetarian keto burger! With hearty Portobello mushrooms, rich cheese, and a perfectly fried egg, all tucked between homemade keto buns, it’s not just for vegetarians. Meat lovers will be impressed too! Whether you’re committed to a vegetarian keto lifestyle or just curious, this burger is sure to become a go-to in your recipe collection.

Vegetarian Keto Just Got Easier

I know that sticking to a low-carb, keto diet can be challenging if you don’t eat meat. That’s why this burger is such a game-changer. It’s packed with flavor, satisfying, and totally meat-free. If you’re interested in learning more about vegetarian keto options, check out this post on vegetarian keto diets.

Recipe Tips and Swaps

Before you dive in, here are a few tips and variations to help you get the most out of this vegetarian keto burger.

• Marinating the Mushrooms: For the best flavor, let the mushrooms marinate for up to an hour. This allows them to soak in all the garlic and herb goodness. If you’re short on time, you can skip the marinating step, but the extra flavor is worth it!
• Cheese Choices: While cheddar or gouda work great in this recipe, feel free to swap in your favorite hard cheese. Swiss or provolone would be delicious alternatives.
• Egg Cooking Tips: To get perfectly round eggs for your burger, use pancake molds or mason jar lids. Cook the eggs until the whites are set, but the yolks are still a bit runny—this adds a creamy richness to the burger.
• Bun Options: The recipe calls for homemade keto buns, but if you’re in a pinch, you can use store-bought low-carb buns. Just make sure to check the ingredient list as most ready-made options are neither low-carb, nor healthy. Also, don't forget to toast them lightly on a griddle for added texture.

I can't eat nuts. Is there a nut-free option for the buns?

Good news, there's a nut-free keto bread roll recipe! If you can't eat nuts, you can use our Nut-Free Keto Buns instead of our classic Keto Buns.

Can I make these vegetarian keto burgers dairy-free?

Yes! If you’re avoiding dairy, you can skip the cheese or use a dairy-free cheese alternative that melts well.

Serving Suggestions

This burger is best enjoyed fresh, but you can prep the components ahead of time. Store the buns at room temperature for up to three days, and keep the cooked mushrooms and eggs in the fridge for up to two days. Assemble just before serving for the best taste and texture.

More Vegetarian Keto Recipes You'll Love

Looking for more vegetarian options? There's hundreds of vegetarian keto recipes here and in our app! Here are some of our readers' favorites:

• Low-Carb Baked Ricotta Dumplings
• Keto Pumpkin & Spinach Cannelloni
• Vegetarian Keto Lasagna

More Keto Burger Recipes You Might Like

And if you love burgers, below are some of our readers' favorites:

• Bunless Big Mac Burger
• The Best Keto Cheeseburger
• Keto Chicken Portobello Burgers
• Keto Blue Cheese Burger
• Low-Carb Italian Stuffed Chicken Burgers
• Low-Carb Chorizo Guacamole Bunless Burgers
• Plus plenty more Keto Burger Recipes and condiments that go with them!

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Step-by-step

1. Make the Ultimate Keto Buns. Prepare the mushrooms for marinating. Season with salt and pepper, add crushed garlic and freshly chopped herbs and ghee, preferably melted. Keep some of the ghee for frying the eggs.

2. Keep the mushrooms at room temperature and marinate for up to an hour. Although marinating is highly recommended, you can skip it if you don't have time.

   

3. Place the mushrooms top side up on a hot griddle pan or a regular pan. Cook over a medium-high heat for about 5 minutes. Then, flip on the other side and cook for 5 more minutes.

   

4. Take off the heat. Flip back on the top side and top each of the mushrooms with cheese slices. Just before serving, place under a broiler for a few minutes until the cheese has melted.

   

5. Meanwhile, fry the eggs on the remaining ghee. You can use pancake molds to create perfect shapes for the burgers. Cook the eggs until the egg white is opaque and the yolks still runny. Then, take off the heat.

   

6. Cut the buns in half and place each halve, cut side down on a hot griddle pan and cook for 2-3 minutes until crispy.

   

7. Start assembling the burgers by adding a tablespoon of mayo on each of the keto bun halves. Top with the Portobello mushrooms.

   

8. Add fried eggs a slices of tomato and lettuce. Serve any remaining lettuce aside. The burgers are best eaten fresh. The burger buns can be stored at room temperature for u to about 3 days.

   

Recipe

The Best Vegetarian Keto Burger

★★★★★4.7 (198 ratings)

A tasty vegetarian low-carb recipe using homemade keto burger buns, portobello mushrooms, perfectly fried ...

Hands on

15m

Overall

20m

Servings

2

9.1 g

Net carbs

23.3 g

Protein

55.2 g

Fat

638

kcal

1 serving2 servings3 servings4 servings5 servings6 servings7 servings8 servings9 servings10 servings11 servings12 servings

US + metricMetricUS

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Ingredients makes 2 servings

• Marinated & grilled mushrooms:
• 2 medium large flat mushrooms such as Portobello (150 g/ 5.3 oz)
• 1 tbsp ghee or virgin coconut oil (15 ml)
• 1-2 tbsp freshly chopped basil or 1 tsp dried basil
• 1 tbsp freshly chopped oregano or ¹/₂ tsp dried oregano
• 1 clove garlic, crushed
• pinch of sea salt and ground black pepper
• Burgers:
• 2 Ultimate Keto Buns
• 2 tbsp paleo mayonnaise (30 g/ 1.1 oz) - you can make your own
• 2 large eggs
• 2 slices hard cheese such as cheddar or gouda (40 g/ 1.4 oz)
• 1 cup mixed lettuce

Instructions

1. Make the Ultimate Keto Buns. Prepare the mushrooms for marinating. Season with salt and pepper, add crushed garlic and freshly chopped herbs and ghee, preferably melted. Keep some of the ghee for frying the eggs.

2. Keep the mushrooms at room temperature and marinate for up to an hour. Although marinating is highly recommended, you can skip it if you don't have time.

3. Place the mushrooms top side up on a hot griddle pan or a regular pan. Cook over a medium-high heat for about 5 minutes. Then, flip on the other side and cook for 5 more minutes.

4. Take off the heat. Flip back on the top side and top each of the mushrooms with cheese slices. Just before serving, place under a broiler for a few minutes until the cheese has melted.

5. Meanwhile, fry the eggs on the remaining ghee. You can use pancake molds to create perfect shapes for the burgers. Cook the eggs until the egg white is opaque and the yolks still runny. Then, take off the heat.

6. Cut the buns in half and place each halve, cut side down on a hot griddle pan and cook for 2-3 minutes until crispy.

7. Start assembling the burgers by adding a tablespoon of mayo on each of the keto bun halves. Top with the Portobello mushrooms.

8. Add fried eggs a slices of tomato and lettuce. Serve any remaining lettuce aside. The burgers are best eaten fresh. The burger buns can be stored at room temperature for u to about 3 days.

Nutrition per serving, 1 burger

Carbs 6%Protein 15%Fat 79% of calories

Net carbs

9.1 g

Total carbs

19.2 g

Fiber

10.1 g

Sugars

4.4 g

Protein

23.3 g

Fat

55.2 g

Saturated fat

18.5 g

Calories

638 kcal

Sodium

896 mg · 39% RDA

Magnesium

116 mg · 29.1% RDA

Potassium

870 mg · 43.5% EMR

Nutrition by ingredient

Per 1 burger	Net carbs	Protein	Fat	kcal
Portobello mushrooms, fresh	1.9 g	1.6 g	0.3 g	17
Ghee	0 g	0 g	15 g	136
Basil, fresh	0.1 g	0.2 g	0 g	1
Oregano, fresh	0.5 g	0 g	0 g	5
Garlic, fresh	0.5 g	0.1 g	0 g	2
Salt, pink Himalayan rock salt	0 g	0 g	0 g	0
Pepper, black, spices	0 g	0 g	0 g	0
Ultimate Keto Buns, homemade (KetoDiet app)	4.3 g	10.1 g	15.9 g	208
Mayonnaise	0.1 g	0.2 g	12.5 g	111
Egg, whole, fresh, raw (free-range or organic eggs)	0.4 g	6.3 g	4.8 g	72
Cheddar cheese	0.6 g	4.6 g	6.7 g	81
Lettuce, mixed leaf salad	0.2 g	0.2 g	0 g	2
Tomatoes, fresh	0.5 g	0.2 g	0 g	4
Total	9.1 g	23.3 g	55.2 g	638

Serving size 1 burger

• Gluten free
• Pork free
• Avocado free
• Fish free
• Shellfish free
• Beef free
• Pescatarian
• Vegetarian