Place a large strainer over a bowl. Line it with a thin kitchen towel or 2 layers of cheesecloth. Pour the milk, cream, and sea salt into a stainless steel or enameled pot.
Bring to almost a full boil, stirring occasionally. Right before it starts fully boiling, remove the pot from the heat and pour in the lemon juice. Let the mixture sit for around 10 minutes or until it curdles. Pour the mixture into the lined strainer and allow it to drain for 30 minutes.
Transfer the ricotta to a bowl for immediate use or store in a tupperware for later use. Ricotta will keep refrigerated for up to 4-5 days.