Mushroom and Mozzarella Sourdough Toastie
Browned mushrooms and low-moisture mozzarella fill two pressed sourdough sandwiches, with crisp edges and a melted cheese center.
Cook the mushrooms until the pan is dry before building these sandwiches. Their browned edges bring the flavor, while low-moisture mozzarella melts without flooding the bread.
A sandwich press makes this easy, but a skillet and a little gentle pressure work too. Cut the toasties after a brief rest so the hot filling stays between the slices.
Mushroom and Mozzarella Sourdough Toastie
- Makes
- 2 servings (1 sandwich made with 2 slices each)
- Prep · estimate
- 12 min
- Cook · estimate
- 20 min
- Total · estimate
- 32 min
Ingredients
- 4 slices (200 g total) unseeded sourdough, about 1 cm / ⅜ inch thick
- 250 g cremini or chestnut mushrooms, wiped clean and sliced 5 mm thick
- 120 g low-moisture mozzarella, coarsely grated
- 2 tsp (10 ml) olive oil
- 10 g softened unsalted butter, for the outer bread surfaces
- ½ tsp fresh thyme leaves, optional
- ⅛ tsp fine salt
- ⅛ tsp freshly ground black pepper
Method
Brown the mushrooms
Heat the oil in a wide skillet over medium-high heat. Add the sliced mushrooms and spread them out. Cook for 8–10 minutes, stirring occasionally, until their released water has evaporated and the edges have browned. If the pan is crowded, use two batches and allow more time.
Season and let the steam escape
Add the salt, pepper and optional thyme. Stir for 30 seconds, then move the mushrooms to a plate. Let them stop steaming for 2–3 minutes while you heat a sandwich press to medium, following its instructions.
Build two sandwiches
Spread the butter thinly over one side of all four bread slices. Set two slices buttered-side down. Put 30 g mozzarella on each, divide the mushrooms between them, then add the remaining cheese, 30 g per sandwich. Close with the other bread slices, buttered-side up.
Press until the cheese melts
Cook the two sandwiches in the press for about 5–7 minutes, until the bread is golden and the mozzarella is melted throughout. Close the press gently instead of crushing the filling out. If only one fits, cook in batches and allow extra time.
Rest and cut
Rest the sandwiches on a board for 1 minute, then cut each in half. Serve while the cheese is warm and the crust is crisp.
Developed for home use; not kitchen-tested by Sourdough Bench. Times are estimates; use the doneness cues in the steps.
Small things that help
- Dry filling is the key
- Do not transfer a pool of mushroom liquid into the sandwiches. Continue cooking until a spatula drawn through the pan leaves no watery trail.
- Use modest heat for thick bread
- If the outside browns before the cheese melts, lower the press temperature. Slices much thicker than 1 cm need longer to heat through.
Make it your own
- Use a skillet instead of a press
- Cook over medium-low heat for roughly 3–4 minutes per side, pressing lightly with a spatula. Cover briefly if the cheese needs help melting. Work in batches if necessary.
- Use fresh mozzarella
- Drain it very well, pat dry and use 100 g torn into small pieces. It gives a wetter filling, so keep the mushroom mixture especially dry.
- Choose another mushroom
- Use the same weight of sliced button or oyster mushrooms. Cook to the dry, browned stage rather than relying only on the timer.
Make ahead & storage
Refrigerate cooled cooked mushrooms in a covered shallow container within 2 hours, or 1 hour above 32°C/90°F. Keep at 4°C/40°F or colder and use within 2 days for this make-ahead filling. Assemble fresh if possible. Reheat a refrigerated cooked sandwich until its center reaches 74°C/165°F.
Dietary notes
Ingredients to check
Contains wheat and milk. For a vegetarian sandwich, choose mozzarella made with vegetarian rennet; cheese labels vary.
Before you start
Why use low-moisture mozzarella?
It melts into a stretchy layer with less loose liquid than fresh mozzarella. Grating it helps the center warm before the bread gets too dark.
Can I cook the mushrooms the night before?
Yes. Chill them promptly in a shallow covered container, then keep refrigerated. A cold filling can take longer to heat, so use moderate heat and check the middle.
Why has my toastie turned soggy?
The mushrooms may still have held cooking liquid, or the bread may be too thick to crisp quickly. Dry the filling in the pan and use the recommended slice thickness.
Sources & inspiration
- Dear兜兜: Brunch pairing ideas on Xiaohongshu
Pairing inspiration only. Sourdough Bench developed the ingredient amounts and method independently; this is not a transcription of the original recipe.
- FoodSafety.gov: Four steps to food safety
Preparation and refrigeration guidance for perishable ingredients.
- FoodSafety.gov: Safe minimum internal temperatures
Temperature guidance for reheating leftovers.
Recipe writing and serving illustrations are created for Sourdough Bench. Inspiration credits identify the source of an idea; they do not imply that another author tested this recipe. How we publish.
