If you can not find tomatoes with the added roasted garlic and onions, you can substitute a standard can of petite diced tomatoes and add 1 tablespoon of finely minced garlic, and saute ½ cup of onions with the shrimp. You can also use a can of mild Rotel tomatoes if desired. I would be careful with the spice/heat level if using canned tomatoes with any type of peppers added to be sure your final results are not too overpowering with spice.