Tricolor Chocolate Mousse

Directions

1. You will need an 8x3 inch cheesecake pan with a removable bottom or an 8x3 inch dessert/cake ring plus an 8-inch cardboard cake circle. You also need an instant-read thermometer and a metal icing spatula that's at least 8-inches long. A propane torch is optional.
2. First make the base for the dessert. If using a cake/dessert ring, place it on a flat plate or tray.
3. Trace an 8-inch circle on a piece of parchment paper. Turn parchment upside down on a baking sheet (you should still see the tracing through the paper) and tape the edges to the baking sheet to keep them from curling later. Melt the ounce of chocolate gently in a small bowl set in a pan of almost simmering water. Spread the chocolate evenly in the traced circle. Refrigerate for 10 minutes or until hardened. When hard, remove tape. Turn paper upside down and peel gently away from chocolate disk. Place the disk in the bottom of pan or ring—if it breaks , simply put the pieces in place (it won’t be won’t be noticed). Refrigerate the pan/ring.
4. To make the bittersweet mousse: Place the chocolate and butter in a medium-large heatproof bowl in a wide skillet of almost simmering water. Stir frequently until the chocolate is nearly melted. Remove the bowl from the heat—leaving the heat on—and stir until completely melted and smooth. Set aside.
5. In a medium stainless-steel bowl, whisk the eggs with the sugar until well blended. Whisk in the water. Set the bowl in the skillet and stir constantly to prevent the eggs from scrambling, until the mixture registers 160 degrees on an instant-read thermometer. (You may have to remove the bowl from the skillet to take the temperature unless you are agile enough to both stir and hold and read the thermometer at the same time!). Rinse the thermometer stem in the hot skillet water between readings. Remove the bowl from the skillet.
6. With an electric mixer, beat the eggs at high speed for 3 to 4 minutes, or until they have a texture like softly whipped cream. Fold one-quarter of the eggs into the warm chocolate. Fold in half of the remaining eggs until nearly blended. Add the rest of the eggs and fold just until evenly incorporated. Immediately, before the mousse begins to set, scrape it into the cake pan or dessert ring and spread it evenly. It should fill the pan not quite half full—in the unlikely event there is any extra, scrape it into small bowl. Refrigerate the pan (and any extra marquise) while preparing the milk chocolate mousse.
7. Make the Mocha Mousse: Place the milk chocolate and espresso in a medium stainless-steel bowl. Bring the water in the skillet back to a simmer. Turn the burner off (if your stove is electric, remove the skillet from the burner) and wait 30 seconds before placing the bowl of chocolate in the water. Stir constantly until the chocolate is melted and smooth. Do not turn the burner back on under the skillet unless absolutely necessary, and then only briefly. Remove the bowl from the hot water. Let the chocolate cool to 85-90° F—a small dab on your upper lip should feel faintly cool, not cold. (If the chocolate is too cold, the mousse may turn out grainy; if necessary, set the bowl in the pan of warm water again for a few seconds before the next step.)
8. Whip the cream in a small bowl, just until it is thickened and slightly fluffy, and barely beginning to hold a shape: When you tilt the bowl, it should flow to one side, fluffy but still pour able and not at all stiff. Scrape the cream into the bowl of chocolate and fold carefully but quickly just until the two are incorporated. The mousse should seem much too liquid and soft—it will firm up later. Immediately scrape it into the pan on top of the marquise, filling half of the remaining space (to leaving room for the final mousse). Scrape any extra mousse into the bowl atop the leftover marquise. Refrigerate the pan and extra mousse while preparing the last one.
9. Make the white chocolate mousse: Repeat the steps for making the mocha mousse (above), using the ingredients for the white chocolate mousse. Immediately scrape the mousse into the pan on top of the mocha mousse. Quickly spread the mousse with a long metal spatula, leveling it against the rim of the pan. Scrape extra mousse into the bowl atop the mocha mousse.
10. Refrigerate dessert for 6 or more hours, before unmolding. Dessert may be completed to this point and refrigerated in the pan, covered, up to 2 days in advance. Or, wrap and freeze for up to 2 months.
11. To unmold mousse **from a dessert ring**, tilt the ring and slide a cardboard cake circle under the dessert. Warm all sides of ring briefly with a hot, wet, wrung out towel, or a propane torch. Immediately slip ring off dessert by pulling it upward with both hands. **From a cheesecake pan**, place pan on top of a large food can or similar heavy object (taller than the height of the dessert, but smaller in diameter than the bottom of the pan). Warm sides of pan as described. Slide sides of pan down to remove from dessert.