Remove the stems from the tomatoes and make shallow cross cuts on the surface.

Boil water in a pot and blanch the tomatoes briefly. Remove them and use the same pot to cook the pork slices until done. Skim off any scum, then cook the udon noodles according to package instructions. Wash the noodles under cold water and drain. Peel the tomatoes in cold water.

Dice the peeled tomatoes into 1cm cubes and mix them in a bowl with the seasonings (vinegar, soy sauce, olive oil, garlic, salt, and pepper) to make the tomato sauce.