Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.

In a mixing bowl, whisk the eggs with milk, salt, and pepper until smooth and slightly frothy.

In a skillet over medium heat, melt a tablespoon of butter and scramble the egg mixture until soft and fluffy, about 3–5 minutes.

Slice croissants in half and place them cut side up on the baking sheet. Toast in the oven for about 5 minutes.

Assemble the sandwiches by layering cheddar cheese, followed by scrambled eggs, and bacon or sausage on the bottom half of each croissant.

Top each sandwich with the other half of the croissant and serve warm, optionally with fruit or coffee.