Low FODMAP caramelised onion and mushroom grilled cheese (gluten free) - George Eats

Ingredients

• 10-25 g butter (salted or unsalted)
• 60-80 g pickled white onion ((see FODMAP notes in the body of the post))
• 20 ml (1 tablespoon)* maple syrup
• 125 ml (1/2 cup water)* or as needed
• Salt (to your tastes)
• Splash of white wine vinegar (to deglaze the pan (optional))
• 75-125 g Oyster mushrooms (torn or chopped)
• 3-4 + sprigs of thyme (woody stems removed)
• Seasoning (to your tastes)
• 10 g butter (if needed)
• 10-20 g butter (just to grease the pan)
• 25-50 g good melting cheese (freshly grated (I used gruyere))
• 25-50 g sharp cheddar (freshly grated (truffled would be delicious))
• 2 thick cut slices of gluten free bread
• 1-2 teaspoons Dijon mustard (optional (choose a brand without garlic, I like Maille))
• 1-2 teaspoons mayonnaise (optional but creates a lovely browned crust)
• Drizzle of truffle oil (optional but very indulgent)
• Sea salt flakes