How to Make It
Make the garlic aioli Place the roasted garlic, raw garlic, egg yolks, and lemon juice in a blender. Blend on high to break down the ingredients and mix them together.
With the motor still running on low speed, slowly drizzle the oil into the garlic and lemon mixture until all has been incorporated and you have a thick mayonnaise consistency.
Transfer the aioli to a mixing bowl and fold in the lemon zest.
Season with the salt, taste, and add more if necessary.
Make the deviled egg spread Place the eggs in a large pot and cover with cold water. Bring to a boil over medium-high heat. Once the water comes to a boil, turn off the heat and cover. Let the eggs sit for 11 minutes.
Drain the water and immediately transfer the eggs to a large bowl of cold water with ice in it. This “shocking” method will stop the egg from cooking. Once the eggs are completely cool, remove from the cold water and, with the shell still on, break each egg in half in order to remove just the yolk. Discard the shell and, if you’d like to, save the whites for salads or snacking.
Place the yolks in a food processor. Pulse the processor until the yolks are broken up.
Add the garlic aioli and mustard and pulse until well combined.
Transfer the mixture to a bowl and gently fold in the crème fraiche.
Season with the salt, gently stirring to combine. Taste and add more salt if necessary.
Make the crostini Preheat the oven to 375°. Brush each piece of bread with olive oil. Arrange the bread in an even layer on a sheet pan and place it in the oven to get crusty and golden on the outside, but still soft in the middle. This should take approximately 3–5 minutes.
Transfer the deviled egg spread to a plastic storage bag and seal, or a pastry bag if you have one. If using a plastic storage bag, snip a small hole in the corner that is about a 3⁄4-inch long.
Pipe the spread onto the surface of the toasted bread, sprinkling each with ground chili flakes. Using a microplane, grate the bottarga over the top of each slice before serving.