For great keto lunches, it can sometimes be hard—at least until you get the hang of it—to avoid bread when you get a sandwich craving. In this instance, though, portabello mushrooms are so, so much more flavorful than any open-faced sandwich has any right to be. Even better, it’s a quick recipe, so you can readily through it together on the go.

PORTABELLA TUNA MELTS
Category: Lunch
Calorie Count: 644 (2 melts)
Macronutrient ratio: Carb-induced calories—5%
Protein: 39 grams Carbohydrates: 9 grams Total Fat: 51 grams
Ingredients
Mushroom buns
- 4 portabello mushrooms or other large flat mushrooms according to preference
- salt to taste
- pepper to taste
- 1 tablespoon butter
Filling
- 2 cans tuna drained
- 1/4 cup mayonnaise
- 2 tablespoons lemon juice
- 1 celery stalk finely chopped
- 2 spring onions sliced
- 2 tablespoons chives chopped
Topping
- 1 tomato
- 4 slices Swiss cheese or other cheese as desired
- 2 tablespoons olive oil
Instructions
- We're going to start by making our mushroom buns. Simply clean your mushrooms well with a damp paper towel, removing the stems, before seasoning with salt and pepper to taste, placing in a hot oven-safe pan greased with butter, cooking bottom-side up 1-2 minutes before flipping over, placing a lid on the pan to cover, and cooking an additional 5-7 minutes—until tender, but still firm—before removing from heat.
- Next, make your tuna filling. Start by placing the drained tuna in a bowl, adding the mayonnaise, lemon juice, celery, spring onions, and chives. Mix well with a fork, seasoning with salt and pepper to taste. Meanwhile, preheat your broiler.
- Make your topping by cutting the tomato into 4 slices. Set aside briefly. Next, divide your tuna mixture into 4 parts and spoon on top of each cooked mushroom. Top with a tomato slice and cheese slice before placing under the broiler for 3-5 minutes, just enough for the cheese to melt. Drizzle with olive oil and serve immediately.
Notes
Tools Needed:
- Large oven-safe pan
- Spatula
- Serving plates