In a small bowl, mix mayonnaise and salsa until well combined.
Spread the salsa mayo evenly on one side of each bread slice.
Layer turkey, green onions, and pepper jack cheese onto half of the bread slices.
Top with the remaining slices of bread, mayo-side down.
Heat butter in a skillet over medium heat until melted.
Place sandwiches in the skillet and cook for 3-4 minutes per side, until golden brown and crispy.
Press gently with a spatula to ensure even toasting and melty cheese.
Remove from heat, slice, and serve hot with your favorite side!