Dinner

Beef Burger in Portobello Buns

Name: Beef Burger in Portobello Buns
Prep time: 20 min
Total time: 20 min
Yield: 1 serving
Ingredients: 160 g Beef mince, 5% fat; 2 large, about 160 g Portobello mushrooms; 25 g Reduced-fat cheddar; 60 g Tomato; 30 g Red onion; 30 g Gherkins; 30 g Lettuce; 1 tsp, about 6 g Dijon mustard; 4 sprays Olive oil spray; To taste Salt; To taste Black pepper

A 5% mince burger with melted cheddar, gherkins and mustard, held between two roasted portobello mushrooms in place of a bun. 46 g of protein for 338 kcal.

Calories: 338kcal
Protein: 46g
Fat: 13g
Carbs: 7g

Per serving, makes 1. 20 minutes of work. Published 8 September 2026.

Allergens

Milk
Mustard

Pickles in vinegar often list sulphites. Check the jar.

Flags follow UK labelling rules and come from the ingredients as listed, not from any particular brand. Check the packet before cooking for somebody with an allergy.

Ingredients

Beef mince, 5% fat160 g
Weighed raw. Standard 20% mince is nearly twice the calories at the same weight.
Portobello mushrooms2 large, about 160 g
Reduced-fat cheddar25 g
Tomato60 g
Red onion30 g
Gherkins30 g
Lettuce30 g
Dijon mustard1 tsp, about 6 g
Olive oil spray4 sprays
Counted at a quarter of a gram per spray, which is what the nozzle on most bottles delivers. Four sprays is 9 kcal.
SaltTo taste
Black pepperTo taste

Method

Heat the oven to 220°C. Remove the mushroom stalks, spray both sides, season and roast gill side down on a tray for twelve minutes.
Season the mince with salt and pepper only and shape into one patty a little wider than the mushrooms. Press a dimple into the middle.
Fry in a hot sprayed pan for four minutes a side. Lay the cheese on top for the last minute with a lid on so it melts.
Spread the mustard on one mushroom, add the burger, tomato, onion, gherkins and lettuce, and close with the other mushroom.

Worth knowing

The bun is the thing that changes. A brioche bun is 250 kcal; two portobellos are 24 and the burger tastes more of beef.
Salt and pepper only in the mince. Egg and breadcrumbs make meatloaf, and a 5% burger holds together fine without them.

Other dinner recipes that share ingredients with this one, or every dinner between 300 and 450 calories a serving.

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Macros are calculated from the weights listed above using standard food composition values, and will shift with your own brands and measuring. Weigh what you can. This is a recipe, not dietary advice. The full health disclaimer is below.