Melt butter in a small saucepan and brown slightly. Cool and set.
Place fat in a large enough bowl and beat with the whisks of a mixer until creamy. Add sugar and salt. Gradually knead in flour. Form the dough into a roll (4 cm ø) and wrap in plastic wrap and chill for at least 1 hour (or freeze for 20 min).
Cut the roll into slices about 1/2 cm thick and place the slices on a baking tray lined with parchment paper. Place in the oven heated to 175 °C and bake for about 10 minutes.
Remove the parchment paper with the cookies from the baking tray and cool completely, the cookies are firm only after cooling.