1. Preheat the oven to 425 degrees F. Line a 12-cup muffin tin.
2. Whisk together flour, sugar, salt and baking powder into a bowl. Cut the butter into chunks and pinch it into the dry ingredients with your hands. This takes a few minutes to do, but make sure the butter and dry ingredients are fully combined.
3. In a separate bowl lightly beat the egg and milk. Pour them into the dry ingredients and stir with a wooden spoon until fully combined. Note, the mixture will look odd and a little gluey, but this is totally normal.
4. Stir in the strawberry pieces until just combined.
5. Fill each cup ¾ full. Bake the muffins for 20 minutes or until tops are golden and spring back to the touch.