Preheat a panini press, grill pan, or skillet over medium heat
Slice bread such as ciabatta, focaccia, sourdough, or baguette
Spread butter, olive oil, or mayonnaise on the outside of the bread
Add fillings such as cheese, meat, vegetables, or spreads to the inside
Close the sandwich and press it gently
Place the panini in the press, grill pan, or skillet
Cook until the bread is golden and crisp and the cheese is melted
Flip if using a skillet or grill pan
Remove the panini from the heat
Let it rest briefly
Slice and serve