Combine the first four ingredients in a food processor and process until smooth. Add the egg yolks and pulse to combine. Process the mixture continually while adding the olive oil to allow it to emulsify. Remove the mixture to a bowl and season to taste. Wrap the bowl with plastic wrap and refrigerate.

Completely dry the snails and transfer to a small container. Pour the buttermilk over the snails and cover the container with plastic wrap. Place in the refrigerator and allow the snails to marinate for four hours. Heat your preferred medium for deep frying to 350 degrees. Blend the corn flour, all purpose flour, salt, and pepper in a bowl or plastic bag (easier for clean-up). Remove the snails from the buttermilk and toss in the dry mixture. Shake the excess dry batter from the snails. Spear a tomato with a skewer. Follow the tomato with a battered snail, another tomato, and a final snail. Repeat the process with the remaining skewers and set aside. Cut away the tips of the French loaf and slice the remainder into one inch-thick slices. Blend the oil and garlic together and brush or rub the mixture into the cut sides of the bread. Using a grill or hot oven, toast the slices until browned and crispy. Set aside. Deep fry the prepared skewers until the snails have crisped and the skin on the tomatoes has wrinkled and begun to peel away from the flesh (about 1 ½ to 2 minutes). Remove the skewers to paper towels and remove frying medium from the heat. Pour the aioli into a shallow bowl and center the bowl on a serving platter. Arrange the toasted bread around the bowl on the platter. Stick the skewers into the toast at a slight angle so that they lean towards the aioli. Garnish with chopped parsley and alfalfa sprouts. Serve immediately as the snails will quickly lose their heat.