I started making these on a Tuesday night when I had half a block of Havarti and a bag of cremini mushrooms that needed to be used up. Didn’t expect much. Now they’re in pretty heavy rotation at my place.
The trick is roasting the mushrooms first — properly, in a hot toaster oven with some garlic and thyme — before they ever touch the bread. Mushrooms have a ton of water in them, and if you skip this step and just pile them raw on top, you end up with soggy bread. Nobody wants that. Roasting concentrates the flavor and gets them a little caramelized around the edges, which makes a real difference. A good toaster oven baking pan with a rim helps a lot here — flat pans let the mushroom liquid drip everywhere.
Havarti is underrated for melting. It goes smooth and creamy without getting greasy, and the dill variety (if you happen to find it) adds this faint herby note that works really well with the thyme. The Dijon underneath the cheese sounds like a small detail but it pulls everything together — a little tangy, a little sharp, cutting through the richness of the cheese. You need a reliable toaster oven that can hit a steady 425°F and has a functional broil setting for the final step; most countertop models handle this fine.
These work as a quick weeknight dinner with a simple green salad, or as a lunch that feels more put-together than a sandwich. Four open-face melts, about 25 minutes start to finish, and almost everything comes from pantry staples.
Toaster Oven Crispy Havarti and Roasted Mushroom Open-Face Melts with Dijon and Fresh Thyme
Thick toast loaded with garlicky sautéed mushrooms, a smear of Dijon, and melted Havarti — broiled in the toaster oven until bubbly and golden at the edges. Ready in under 25 minutes and genuinely satisfying.
Ingredients
Instructions
-
Preheat your toaster oven to 425°F on the bake setting. Line the pan with foil — mushrooms release liquid and you don't want to scrub that later.
-
Toss the sliced mushrooms with 1 tablespoon of olive oil, the garlic, thyme, salt, and pepper. Spread them in a single layer on the foil-lined pan. Don't crowd them or they'll steam instead of roast.
-
Roast for 10 to 12 minutes, until the mushrooms are shrunken, golden at the edges, and smell nutty. Pull the pan out and push the mushrooms to one side.
-
Brush the bread slices lightly with the remaining olive oil on both sides. Lay them flat on the pan and slide it back in for 3 minutes just to get the bread a little toasty. Not fully crunchy — just firmed up.
-
Pull the pan out again. Spread each slice with about half a tablespoon of Dijon. Dot a tiny bit of butter over the mushrooms (trust me on this), then pile the mushrooms onto each bread slice. Top with Havarti — be generous.
-
Switch your toaster oven to the broil setting. Broil for 2 to 3 minutes, watching closely, until the cheese is melted and starting to bubble with a few golden spots. Every toaster oven broiler is a little different, so check at 2 minutes.
-
Let them sit for one minute before eating — the cheese is lava hot. Scatter fresh parsley over the top and serve immediately.
Notes
Havarti melts beautifully but if you can't find it, low-moisture mozzarella or Gruyère also work well. Whole grain Dijon has a bit of texture that I really like here, but smooth Dijon is fine too. If your mushrooms look watery after roasting, blot them with a paper towel before piling onto the bread — soggy toast is nobody's friend. These don't save well; eat them fresh off the pan.
Nutrition
Rate this recipe
Made it? Tap a star to rate.
Written by
Emma is a home cook who loves coaxing big flavor out of a toaster oven — from crispy roasted vegetables to easy weeknight dinners and sweet treats. She develops and tests Toastera's recipes for small-appliance kitchens.
Free: the Toaster Oven Cheat Sheet
Get the printable cheat sheet (temps, cook times & safety tips) plus new recipes. No spam, unsubscribe anytime.
