This is a simplified (and, I think, better) version of a dish I posted on the old FLDG. It's based on something I've eaten regularly at a little hole-in-the-wall outside of Alba.
First, we make a porcini fonduta. Take 2 or 3 medium porcini (you MUST use fresh here), trim, and cut into 3 mm thick slices. Mince one or two shallots. Mince three or four cloves of garlic. Heat a few tablespoons of olive oil in a pan, then add the shallots and garlic, stir, then add the porcini. Sautee with lots of flipping and stirring until the porcini start releasing some juice and the pan gets some brown stuff starting to form. Deglaze with a splash of white wine. Let cool.
In a saucepan over medium heat, melt a couple tablespoons of butter. When it foams up, add about a tablespoon or two of flour and whisk to form a roux. Continue heating until the flour barely changes color. Turn up the heat a bit and add a cup of milk, whisking vigorously the whole time. When the roux and milk are incorporated, add a few pinches of salt. Continue whisking until the mixture thickens. Take the pan off the heat, grate in a little bit of nutmeg, add a pinch of white pepper, and a handful of grated Fontina. Stir to incorporate the cheese (if you do this with the pan still being heated, you'll get a stringy mess.
Now, we make the terrina. Preheat an oven to 425 degrees F. Put in a bain marie, then add boiling water to it. Take two 200ml (7 oz) ramekins, grease them (I used Pam and a little EVO), then put some of the mushroom sautee in the bottom of each. Now spoon in some fonduta. Put the ramekins in the bain marie and bake for four minutes; this gets the ramekins and their contents nice and hot.
Crack one perfect egg into each ramekin, then continue baking in the bain marie for about 7 minutes, or until the whites are loose but nearly all-white and the yolk has thickened but not hardened at all. The white right next to the yolk should still not be completely set (the egg will continue cooking even after being removed from the oven).
Remove the ramekins from the bain marie, top with a pinch of fleur du sel, a half pinch of pepper, shaved white truffles, then serve.
If all you have is black truffles, put a slice of truffle on the bottom of the ramekin before assembly and cooking. Shred more black truffle and give it a minute or two sautee in butter, add a dash of dry marsala, then use this to top the dish when it's removed from the oven.
