In a small bowl, mix water and yeast. Keep it aside for 5 minutes.
In a mixer, add flour, sugar, and salt. Then, add the yeast mixture and milk. Mix it until it forms a ball.
Take out the dough and knead it for 5 minutes until it gets soft and firm.
Keep this dough in a greased bowl and keep it for about 30 minutes in the refrigerator.
Dust your work surface with some flour and roll the dough. Make rectangular sheets out of it. Let it rest for 5 minutes.
Meanwhile, give the butter a rectangular shape and place them between the sheets of wax paper and roll them. If it is too warm then, let the butter cool.
Now, place the rectangular sheet of butter on the rectangular dough. Fold the dough until it covers the whole butter slab.
You have to fold it from two sides to cover the butter and form a closed butter-filled dough.
Repeat the same procedure for the remaining dough, dust the dough with dry flour, wrap it with some plastic wrap and refrigerate them for about 24 hours.
After 24 hours, take the dough out of the refrigerator and unwrap it. Trim its sides to form straight edges.
Using a sharp knife, cut the dough in half size or as per your requirement, cut those sheets into halves, cut those strips into a triangular shape.
When the triangle-shaped dough is ready, start with the base and roll them into crescents from the base towards the tip.
Align the baking sheets and put silicone baking mats on them. Place the croissants on them carefully.
Brush the surface of the croissants with beaten eggs. Keep the croissants uncovered and let them rest for 2 hours.
Preheat your oven to 4000F before baking. Bake them for about 15-28 minutes until golden brown. Let them cool and your mini Croissants are ready.