In a sandwich-size zipper bag, pour 1 teaspoon of salt; then squeeze all of the juice of one medium-sized lemon into the same bag. Dissolve the salt as best you can into the lemon juice; it does not need to be perfect.
After opening your tofu package, discard packaging liquid but do not press the tofu. With a sharp knife, slice your tofu into 12-14 slices (place the block of tofu down with the largest side facing up, turn it widthwise (landscape), then slice vertically; see photos for reference). Alternative shaping options: Alternative 1: Dice your tofu into 1/2-inch cubes. Alternative 2: slice the corners off of the (whole) block of tofu to make it into a rounder shape that more closely mimics real buffalo mozzarella, before slicing it into 12-14 round slices; if you do this, you will need to marinate slices from a second block of tofu to compensate for any unused scraps. Alternative 3: Use a very small melon baller to scoop your tofu block into small rounds, adding more tofu from a second block if needed to compensate for any unused scraps.
Pick up the entire block of sliced tofu (or whatever shape you chose) and place into your plastic zipper bag with the lemon juice and salt. Remove as much of the air as you can and seal the bag closed.
Let the tofu marinate in the fridge for a minimum of 4 hours or for a few days. I like to turn the tofu over in the fridge halfway through the marinating process to ensure it absorbs the lemon juice and salt evenly. You can do this without letting the tofu marinate for that long, but it will not taste as cheesy and will likely taste extra salty and lemony because the tofu won't have had a chance to absorb and distribute it as well.
When your tofu mozzarella is marinated and ready to serve, slice tomatoes pieces about the same size as your vegan mozzarella slices. You can also combine large tomato slices with smaller ones, depending on what tomatoes you have.
Assembly option 1: If using large vegan mozzarella slices, place vegan mozzarella slices flat on large plate, and place one large basil leaf (or more smaller ones) on each slice of vegan mozzarella, followed by one large slice of tomato on each vegan mozzarella slice. Add halved grape/cherry tomatoes if using. Sprinkle very evenly with 3/4 teaspoons salt and garnish with optional small basil leaves.Assembly option 2: If using diced vegan mozzarella, dice your large tomatoes into 1/2-inch cubes, or halve your cherry/grape tomatoes. Chiffonade (slice very thinly) your basil leaves. In a medium-sized bowl, add your vegan mozzarella, tomatoes, basil, and remaining 1/2-3/4 teaspoon of salt, and toss until well combined. Serve and enjoy! Should keep in the fridge for 4-5 days.