AMEX has rolled out a new Uber Eats offer. Spend $15 or more and get $5 cash back, up to 5 times. In addition, you can earn an extra 3x AMEX MR on the purchase, up to 500 points. This offer is best added to cards that come with Uber credit, and the AMEX Platinum or Gold are both great choices. This offer should be fairly widely available, so I recommend adding it to all of your cards.
If you’re not familiar with how Uber credit works, you can check out the article below. Note that with this kind of offer, generally the amount after applying credits/reimbursements needs to be more than $15 in order to earn the cash back.