First, we make a porcini fonduta. Take 2 or 3 medium porcini (you MUST use fresh here), trim, and cut into 4-5mm 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, add a few tablespoons of stock, a pinch of chopped sage, salt and pepper, then reduce slightly. Stir in a couple tablespoons of cream or creme fraiche, remove from the heat, then stir in grated fontina until you get a nice, viscous coating on the mushrooms.
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 spoon in some fonduta. Put the ramekins in the bain marie for four minutes.
Remove the ramekins from the bain marie, crack one perfect egg into each of them, then put the ramekins back 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.
Remove the ramekins from the bain marie, put 2 or 3 drops of white truffle oil on each, a pinch of fleur du sel, a half pinch of pepper, then serve.