Start by blending the plum tomatoes and half of the vine ripe tomatoes to a fairly smooth consistency.
Fold in the remainder of the vine ripe tomatoes, watermelon, diced red onion, cucumber, lime juice, bell pepper,celery, salt, black pepper, e.v.o.o., and basil Pulse a few times to break everything up.
Add your crushed red pepper flakes and cilantro taste and add your tobasco to taste.
Notes
What Chef Chris didn't say in his directions but I suggest you do is to let this sit for at least a couple of hours before serving. This is one of those dishes that get better as it sits and will be even better the next day.