Slice the tomato into ¼-inch slices. Dab with a paper towel, drizzle with balsamic, and season with salt & pepper. Set aside.
Spread pesto on all four slices of sour dough or thick bread. Top two of these with seasoned tomatoes. and fresh basil leaves. Add the mozzarella cheese.
Top with the second slice of bread to each sandwich and brush the outside with olive oil.
Place in a single layer in the air fryer basket and cook 4-6 minutes or until golden and melted.
Remove from air fryer and rub the outside of the bread with the garlic clove. Serve warm.