This is Herbie’s version of a French onion soup – enhanced with our fragrant North African spice blend Berbere, and given a hit of umami with porcini powder. You can vary the depth of flavour depending on the stock you use – beef at the richer end of the scale, and vegetable for a lighter soup.
Use the caramelised onion mixture (before stock is added) as a topping for a puff pastry tart, or mix into beaten eggs for a quiche filling.
- Peel onions and slice finely while whole (a mandolin is great for this job).
- Melt butter in a heavy based saucepan then add onions. Cover with greaseproof paper and lid and cook on low, stirring occasionally, for 45 minutes – 1 hour until very soft; there should be very little resistance when pressing a strand between your fingers.
- Add garlic, Berbere, porcini, salt and sugar and cook for a further 10 minutes with the lid removed, stirring a few times.
- Pour in stock of choice and simmer for a final 10 minutes.
- Heat a grill to high. To serve, ladle soup into bowls and top with a slice of baguette (or two) and plenty of grated gruyere. Place bowls under the grill to melt cheese, then carefully remove to a plate to serve. Alternatively, grill cheese on baguette separately and serve on top of soup or on the side.
- Top with a grind of black pepper and eat immediately.