In a large bowl, whisk together the sparkling water, lemon juice, baking soda, sugar, and salt.
Add the calamari and toss to coat. Cover and refrigerate for 2 hours.
To prepare the dressing, place the breadcrumbs and almonds in a food processor and pulse until finely chopped.
Add the garlic, lemon juice, olive oil, Greek yogurt, and mayonnaise.
Process until the mixture becomes smooth and creamy. Season with salt to taste.
Transfer the dressing to a covered container and refrigerate until needed.
After marinating, drain the calamari in a colander. Shake off excess liquid but do not rinse or pat dry.
Arrange the salad greens among four serving bowls or plates.
Top with sliced shallots, tomatoes, and cucumber. Set aside.
In a shallow bowl, combine the flour, cornmeal, and salt.
Heat the vegetable oil in a deep pot to 340°F (170°C).
Line a plate with paper towels for draining.
Working in small batches, dredge the calamari in the flour mixture until lightly coated.
Shake off any excess coating.
Carefully add the calamari to the hot oil without overcrowding the pot.
Fry for 1 to 3 minutes, or until lightly golden and crisp.
Remove with a slotted spoon and transfer to the paper towel-lined plate.
Repeat with the remaining calamari.
Spoon some dressing over each prepared salad.
Top with the warm crispy calamari.
Season with additional salt and freshly cracked black pepper if desired and serve immediately.