This dip is really good. So good, in fact, that my wife and I may have finished off an entire bowl in one sitting while I was writing this for my cookbook. It’s not too creamy since the onions make up a good proportion of the contents. The secret here is to make sure the dip is nice and moist. [I realize I just made 98 percent of you uncomfortable.] I find this dip to be heavier than others, so use a sturdier chip or cracker. I can say from experience that Ritz crackers work well (see note about Wife and me slamming the entire bowl).
Caramelization takes a long time. Like several hours long. But it’s not active time. Once you start cooking the onions, you’ve got plenty of time to work on anything else. So sit back, relax, and have yourself a few cocktails while those babies get sweet, sweet caramel brown.
2 tablespoons (28 g) butter 2 pounds onions (900g or 5–6 cups), 1⁄2-inch dice 1 tablespoon Better Than Bouillon 4 tablespoons dry white wine 3 tablespoons (10 g) fresh thyme 4 ounces (114 g) Gruyère 6 ounces (170 g) crème fraîche (or sour cream) 6 ounces (170 g) good mayonnaise, such as Hellman’s
Add the butter and onions to a large sauté pan and sweat over medium-low heat until the onions caramelize, at least 60 minutes, stirring occasionally to caramelize evenly. If the onions get too dry, add a few tablespoons of water and stir. You’re not trying to brown the onions; you’re trying to caramelize them. If they start browning, turn the heat to low. You should hear a gentle sizzling but nothing more than that.
Add the bouillon, white wine, and thyme to the pan. Turn heat up to medium and reduce the liquid to a glaze. Once you achieve the glaze, move the onions to a bowl.
Add the Gruyère, crème fraîche (or sour cream), and mayonnaise to the bowl with the onions and mix thoroughly to combine.