Caramelized Onion, Mushroom and Asparagus Grilled Cheese

Sometimes short weeks can seem so long.  Maybe it’s the anticipation of a long weekend, or maybe we’re all just due for a little break.  Whatever it is, we over here at Saltwater Daughters do not feel like cooking up a big meal. But no worries, we’ve still got you covered!  Today we’ve got a quick, fancied-up grilled cheese to get you through the day, and there’s no meat, so it’s great for Good Friday as well!  It’s a Caramelized Onion, Mushroom and Asparagus Grilled Cheese!  And yes, it tastes as good as it sounds.

It’s really easy and we only used one pan to cook it all.   All our favourite dishes are made in one pan…mainly because we’re lazy and don’t want to clean more than one dish.  But you can use two pans if you’re so inclined!  All you have to do is caramelize the onion and mushrooms, remove from the pan, fry your asparagus for a few minutes, then assemble and fry the sandwiches.  Easy peasy.  We used ginormous slices of sourdough, which easily fed two.   If your bread slices aren’t so large, make 4 sandwiches instead of two!

Caramelized Onion, Mushroom and Asparagus Grilled Cheese

A tasty upgrade to your everyday grilled cheese with the addition of caramelized onion, mushrooms, asparagus and swiss cheese.


  • swiss cheese, grated
  • 12-16 asparagus spears (thin ones are best)
  • 1 small yellow onion, thinly sliced
  • 100g shiitake mushrooms, stems removed and sliced (or your favourite kind)
  • 4 slices sourdough bread
  • 2 tbsp butter
  • 2 tbsp olive oil, extra virgin
  • dijon mustard


  1. Heat 2 tbsp of olive oil and 1 tbsp of butter in a large pan over medium-low heat.  Add your sliced onion and mushrooms to the pan and cook for 20-30 minutes, until the onions and mushrooms are caramelized.  Remove from pan onto a plate.

  2. Return pan to heat and add your asparagus, and cook for 5 minutes, stirring them around the pan as they cook.  Transfer asparagus to a plate and return pan to heat.

  3. Start to assemble sandwiches by buttering the outside of the bread and putting dijon mustard on the inside of the bread.  Add a little bit of cheese to the bottom slice, top with half the onion/mushroom mixture and asparagus and then top with more swiss cheese.  Close the sandwich and fry until both sides are browned and cheese is melted.