Step 1Heat milk and cream in saucepan over medium-low heat. Just when it boils, remove from heat. Turn on blender to lowest speed and add milk-cream mixture, then flavoring. With blender running, add egg. When thoroughly blended, season with salt and white pepper to taste and strain through fine-mesh strainer into pitcher or glass measuring cup. Set aside for several minutes, then skim foam that rises to top.
Step 2Pour into 4 (2-ounce) custard cups. If foam or bubbles remain on top, skim them off. Place custards in large pan or glass baking dish (if using a metal pan, cover bottom with newspaper). Pour boiling water into pan so that it rises just above the level of the custards in the dishes.
Step 3Cover dish with plastic wrap and bake at 250 degrees about 30 minutes. Check custards by removing plastic and jiggling. When just set--meaning custard will jiggle but is no longer pourable--remove from oven. Refrigerate if serving cold. Set aside until ready to serve if serving warm.
Shallot Custard: Use about 1/4 cup cooked, minced vegetable for every 3/4 cup liquid. In this case, gently caramelize 1/2 cup shallots in dry non-stick pan. Add to hot milk along with egg, puree and strain before baking. Serve this with more caramelized shallots as a canape course or as a garnish for onion soup.
Each serving: 113 calories; 112 mg sodium; 95 mg cholesterol; 10 grams fat; 2 grams carbohydrates; 3 grams protein; 0 fiber.
Extra-Virgin Olive Oil Custard: Add 2 tablespoons very good quality extra-virgin olive oil to liquid along with egg, puree and strain before baking. Serve with Nicoise olive tapenade.
Each serving: 172 calories; 112 mg sodium; 95 mg cholesterol; 17 grams fat; 2 grams carbohydrates; 3 grams protein; 0 fiber.
Tarragon Custard: For herb-infused custards, use 1/4 cup soft herb leaves (herbs with soft stems such as tarragon or chives) or 2 tablespoons hard herb leaves (herbs with hard stems such as rosemary or thyme). Heat herbs with milk-cream mixture, then remove from heat and steep 15 minutes before proceeding. Add egg, puree and strain before baking. Serve with diced orange sections (remove sectional membranes) tossed with a little minced shallot.
Each serving: 120 calories; 113 mg sodium; 95 mg cholesterol; 11 grams fat; 3 grams carbohydrates; 4 grams protein; 0.18 gram fiber.
Bone Marrow Custard: Remove 1/4 cup bone marrow pieces from beef marrow bones. (Ask your butcher to cut bones in half lengthwise so marrow can easily be removed.) Soak in water 24 hours to draw out blood, changing water once or twice. Cut marrow into 1-inch pieces and poach in chicken stock until translucent, 2 to 3 minutes. Marrow tends to dissolve in broth, so it's better to leave pieces larger. Drain stock, add marrow and eggs to heated liquid, puree and strain before baking.
Each serving: 172 calories; 136 mg sodium; 102 mg cholesterol; 17 grams fat; 2 grams carbohydrates; 3 grams protein; 0 fiber.