Brush olive oil on the bottom of all four slices of bread.
Turn bread over and spread each slice with pesto.
Top with cheese, then chicken, spinach, artichoke heart, sun-dried tomatoes, and more cheese.
Place the other slices of bread on top with the olive oil side facing up.
Place each sandwich into your panini press or indoor grill. (Alternately, you can place each sandwich in a heated frying pan).
Press the lid down on the grill or press, and hold down firmly for 30 seconds to a minute. Be sure to use a towel over the lid to protect yourself from any escaping steam. If using a frying pan, press the sandwiches with a smaller pan on top.
Grill until golden. Then remove, slice, and serve immediately.