Lay out four slices of sourdough bread. Spread a generous layer of basil pesto evenly on one side of each slice.

On two of the pesto-covered slices, layer about one ounce of melted fontina cheese, followed by even slices of turkey and juicy Roma tomatoes. Top with remaining pesto-covered slices and press down lightly.

Press the assembled sandwiches gently and brush the outer sides with olive oil.

Preheat skillet to medium-high heat and grill sandwiches for about 3-4 minutes per side or until golden brown and cheese melts.

Flip the sandwiches and cook the other side for another 3-4 minutes until crisp and gooey.

Slice each panini in half diagonally and serve warm.