Pour milk into a small saucepan and bring to a gentle boil over medium heat. Add vinegar (or lemon juice) and remove from heat. Stir mixture slowly until curds form, 1 to 2 minutes.

Line a colander with cheesecloth and set over a bowl. Pour the mixture into the colander to drain. Let curds cool and whey drain for about 15 minutes.

Transfer curds to a bowl and season with salt. Serve or store in an airtight container in the refrigerator for up to 3 days.