Set oven to 500°F (260°C) and line a baking sheet with foil or parchment paper.
In a bowl, combine softened butter, mayonnaise, cheddar cheese, and green chiles (with juices) until evenly mixed.
Slice French loaf lengthwise and spread the mixture generously over both halves.
Bake for 5 minutes, then switch to broil until the cheese is golden and bubbly.
Let the bread cool slightly before slicing for the perfect clean cut.
Slice and enjoy warm, right out of the oven for best texture.
