Many years ago, when I was a bumbling kitchen neophyte, I worked at a restaurant that had a fabulously talented chef. She cooked fabulous food, and had an infectious attitude - unfortunately, fabulous was not the category that you would rate her temperament.
It was not entirely her fault. You see, I was pretty useless in a commercial kitchen back then. I would swan around, slowly following recipes to the letter, and basically having a grand old time. I was what you would call a third leg in those early days. I had no sense of urgency that is required of the job, and this chef was going to instill that urgency into me, any way it took. For me it was a devastating year. Physically and more importantly, emotionally draining, but by the end I had been whipped into shape and could confidently cook for a full restaurant. I took many things with me from that job, knowledge, skills, a nervous tic, friendships and recipes - however I neglected to take the recipe for soubise sauce.
Back then; we just called it "onion and leek sauce", which is pretty much what it was. We served it alongside a warm spinach and feta tart - the obligatory vegetarian option on a omnivorous menu. The tart was pretty good, but the sauce was a revelation. It did not taste overtly of onions; it was rich, yet not cloying, sweet, but never overwhelming. It could partner a range of dishes with elegance and ease. It had depth - a one dimensional dressing this was not - you could taste the complementary elements as it slid across your tongue. Gloriously separate, yet seamlessly in balance at the same time.
For years afterwards the thought of that sauce, or moreover my lack of a recipe haunted me. Salvation appeared with the opening of a new restaurant several years later. It was lauded for their hearty and authentic French country fare, but surprisingly, their greatest source of renown came before the meal. On arrival, they served slices of sourdough, a bowl of olives and an earthenware plate holding soubise sauce. You can imagine my delight when I saw the translation the restaurant reviewer provided - rich French onion sauce.
Armed now with a name, I hit all the classic French cookbooks - Elizabeth David had a recipe, as did Larousse Gastronomique. Larousse also shed some light on the sauce's origins. It declared soubise to be a preparation of pureed onion added to béchamel (I think not), or simply an onion puree, thickened with rice - again wide of the mark as I recalled it. Dishes labelled soubise named were in honour of Charles de Rohan; Marshal of France and Prince of Soubise. It would be a waste not to paraphrase Larousse, when it has such wickedly florid prose to quote. It remarked that M. de Rohan;
"…like other 18th-century French aristocrats, did not despise the culinary art…"
I made all of the recipes, but none were quite the same. I had the foundation - but that elusive taste was never the same. Most obviously, there was a missing haunting anise element that I later added with Pernod. After some experimentation, and not a modest amount of onions, I arrived at this version of soubise - the sauce of my memories.
Peel the onions, chopping off the stem and shoot ends. Cut each onion in half, then into thin half rings. In a medium-sized, heavy based saucepan, melt the butter over low heat and add the onions and garlic. Sweat the onions on this low heat for around 15 minutes. "Sweat" means there should be no sizzle in the pan and the onions should not colour - they will just go soft and slowly turn translucent. Take care with this step, as properly sweated onions will be sweet, while darkened onions will taste bitter.
When the onions have collapsed and are very soft, add the flour and stir well. Add the stock (or milk) and gently bring to the simmer, stirring as it heats to avoid the flour forming lumps. When the flour and stock have been thoroughly combined, add the nutmeg and some salt and pepper. Check the sauce's consistency - if it is quite thin, simmer gently until it thickens slightly; too thick - add a little more stock.
Traditionally, soubise is passed through a sieve at this stage. This involves standing a coarse-meshed sieve over a bowl and rubbing the solids through with a wooden spoon or rubber spatula; and this method does indeed yield the best results - a smooth, yet slightly textured sauce. You can do this step in a food processor - just remember not to over-blend the sauce. You want a little texture left, not a smooth puree.
Return the soubise to a saucepan, and gently reheat. Taste for seasoning, and then add the pastis. Notice how the anise lifts the sweetness of the onions and brings the whole into harmony.
What to serve your soubise with? Lots. It makes an effortless partner to grilled meat and poultry dishes. Dress vegetarian tarts or frittata with a drizzle of soubise. Add some to pasta sauces to provide a nice gloss and added flavour. Top a tuna or swordfish steak with warm soubise and pile on some crisp pancetta, watercress and lemon. If you want, you could even just dip fresh sourdough into it.