In a high speed blender, add your milk, condensed milk (or Greek yogurt), and ice, and blend until combined. Add the strawberries and blend until the desired texture is achieved.
Pour the smoothie into four glasses and enjoy it immediately.
TO STORE: While the strawberry smoothie is best enjoyed fresh, you can store it in the refrigerator for up to 24 hours. Any longer and you'll find the smoothie starts to separate. TO FREEZE: The smoothie cannot be frozen as a whole. Instead, pour the smoothie mixture into an ice cube tray and freeze. When ready to enjoy, break out the smoothie cubes into a blender and blend until thick and smooth. Frozen smoothie cubes can be stored in the freezer for up to 6 months.