Wash tomatoes and score an 'X' on the bottom of each.

Blanch tomatoes briefly in boiling water, then remove and peel.

Dice peeled tomatoes into small pieces.

Slice onions thinly and set aside.

Trim beef sirloin to remove tendons and excess fat.

Sear the beef on high heat in a pan to lock in juices, then dice.

Layer onions, tomatoes, and beef in a pot sequentially.

Simmer on medium heat for 40 minutes without adding water.