Preheat oven to 450˚F.

In a food processor, blend the olive oil, green garlic, and salt. Add 2 tablespoons of the mayonnaise and blend well. Transfer to a small bowl and whisk in the rest of the mayonnaise and the lemon juice.

Arrange the pancetta on two rimmed baking sheets in a single layer. Bake about 10 minutes, until crisp. Transfer to paper towels to drain.

Place toasted bread on a work surface and spread each slice with aioli. Arrange the mizuna on 6 of the slices of toast, then top with the tomatoes, then pancetta. Top with the remaining slices of toast, aioli side down. Slice each sandwich in half, and serve.