2Tbsp olive oil
3 large white onions cut to about 3–4mm/ 1/8th inch
1 large sprig of Thyme
1 tsp flour
¼ cup pale dry sherry (you could use ½ cup dry white wine instead)
½ cup cream
750ml good quality chicken stock or bone broth
Salt & white pepper (I love white pepper here)
2 thick slices of sourdough or one large slice cut in half (it’s important to use a sturdy bread here)
1 clove garlic (optional)
¾ – 1 cup grated Gruyere cheese
Heat the butter and olive oil in a medium-large heavy-based pot and sauté the onion with the thyme for about 10 minutes. Add the flour, season well with salt & pepper and cook for a minute. Add the sherry to deglaze the pan and cook for a further 1 – 2 minutes. Add the cream and allow this to cook for about 4 – 5 minutes until it’s really thick and most of the liquid has cooked off. Add 1 cup of stock and cook for about 2 minutes once again scraping down the pot.
To cook in an Instant Pot: Add this mix to the bowl of the Instant pot with the remaining 500ml of stock and cook on high for 10 minutes. Release the pressure manually. Remove the thyme stalk.
To cook on the stovetop: add the remaining 500ml of stock to the pot and carry on cooking this over low heat for about 30 minutes. Remove the thyme stalk.
When you are ready to serve, preheat your ovens grill/ broiler. Place the bread on a baking sheet and toast on either side for about 2 – 3 minutes until it is a light golden colour. Remove and rub the garlic clove over the toast (optional).
Dish up the soup in 2 ovenproof dishes to just below the rim. Place a slice of toast on each soup and then top with the grated cheese. Place this in the oven about 1/3 of the way down (so not directly under the grill) and grill until the cheese is golden and bubbling and serve. If your oven has a fan and grill setting you can use this combination to keep the soup piping hot