How to Make It
Bring a medium pot of water to a boil over high. Add lima beans; cook until just tender, 12 to 14 minutes. Add corn; cook until tender, about 2 minutes. Drain. Gently toss beans, corn, tomatoes, onion, vinegar, parsley, 2 tablespoons of the oil, 1 3/4 teaspoons of the salt, and 1/2 teaspoon of the pepper in a large bowl. Set aside.
Heat 1 tablespoon of the oil in a large nonstick skillet over medium-high. Add seasoning blend, and cook, stirring occasionally, until liquid has evaporated, about 5 minutes. Transfer mixture to a large bowl; cool 10 minutes. Wipe skillet clean.
Stir salmon, panko, mayonnaise, mustard, egg, and remaining 1/2 teaspoon salt and 1/4 teaspoon pepper into seasoning blend in bowl. Shape salmon mixture into 8 (about 1/3 cup each) 3/4-inch-thick patties, and place on a parchment paper-lined baking sheet. Cover and chill at least 30 minutes.
Heat remaining 3 tablespoons oil in skillet over medium. Cook patties, in batches, until golden brown, 3 to 4 minutes per side, adding additional oil, if needed. Serve croquettes with succotash.