Make the Aioli: Add garlic to a small saucepan, cover by 1/2 inch with cold water, place over medium flame and poach until water comes to a boil. As soon as the water boils, remove from heat, steep for one minute, drain and rinse with cold water to stop the cooking. Wait for garlic to cool completely. Add the garlic, mayonnaise, olive oil, smoked paprika, and lemon juice to a blender or food processor and process until smooth. Do not over mix. Taste and adjust lemon if desired and then add salt, and pepper to taste. Refrigerate to help marry flavors.
Cook Pork Belly: Add pork belly to a non stick pan over medium heat and sear on both sides until golden brown, about 3 to 5 minutes per side; remove to a paper towel.
Build Sandwich: Toast bread, if preferred. Spread both slices of bread with Smoked Aioli; top one slice with lettuce, tomato and pork belly and top with second slice of bread. Slice in half and eat right away.