Keep the bun from becoming soggy
Wipe mushrooms with a damp cloth or rinse briefly and dry carefully; do not leave them soaking. Twist out the stems but keep the gills if you like. A broad spatula supports a softened cap better than narrow tongs. Toast the cut buns so they do not immediately absorb all the mushroom juices. Lettuce adds another light barrier. Spread mustard cream sparingly and offer the remainder alongside instead of overloading the sandwich with sauce.
The recipe
Serves 4
Ingredients
- 4 large portobello mushrooms, about 1 lb / 450 g
- 2 tbsp olive oil
- ½ tsp fine salt
- ½ tsp black pepper
- 4 burger buns
- ⅓ cup plus 1 tbsp / 100 g Greek yogurt
- 1 tbsp whole-grain mustard
- 1 tsp lemon juice
- 4 lettuce leaves
- 1 tomato, sliced
Method
- Mix yogurt with mustard and lemon juice and refrigerate. Clean mushrooms, remove stems and pat the caps dry. Brush with oil and season with salt and pepper.
- Preheat an outdoor grill for medium heat, with a direct cooking area and a separate unheated zone. Clean the grate before adding food. Keep the cooler side clear so pieces can finish gently or move away from any flare-up.
- Grill gill-side down over medium direct heat for 4–5 minutes. Turn and cook another 4–6 minutes until tender but intact. Let excess liquid drain briefly onto a clean plate.
- Toast bun interiors and spread with a little mustard cream. Layer with lettuce, a mushroom cap and tomato and serve immediately. Stored mushrooms are better sliced into a skillet dish later than reheated inside a fully assembled burger.
Storage
Put leftovers into shallow covered containers and refrigerate within two hours, or one hour when the temperature exceeds 90°F / 32°C. Keep at 40°F / 4°C or colder and use within three days. Store dressing separately when possible, and reheat only the portion you plan to eat.
Use grilling equipment only in its intended location and follow the manufacturer’s instructions. Timing is not a substitute for checking doneness.
