Onion sauces in the days before sophistication were rustic affairs, more bitter than sweet, more brown than white. Lard was used to fry the onions, and flour rather than cream was the thickener. Broth was preferred to bouillon. Some recipes called for lemon juice instead of vinegar. Herbs – bay, rosemary, thyme – gave the sauce an aromatic hint. Cloves, egg yolks and mustard were occasional flavourings. And bacon or ham was an expedient ingredient. Interestingly, recipes began to appear in the 1930s with a haute cuisine twist. The onions were cooked in milk, sieved and set aside to breath. Sour cream and egg yolks were added to a light roux, and heated gently with the onions.
350 ml broth 250 g onions, chopped 50 g bacon, diced 45 g flour 15 g lard 5 g mustard (optional) Vinegar, splash 3 cloves (optional) 1 bay leaf (optional) Salt, pinch
Fry onions in lard over a medium heat for 15 minutes, until they begin to take on colour. Stir in flour and cook until the mixture turns light brown. Add bacon, followed a few minutes later by the liquid, less for a thick sauce. Bring to the boil, reduce heat to low and cook for ten minutes until the sauce reaches a smooth consistency. Finish with a splash of vinegar. Aromatic options should be added after the bacon.