Heat the oil in a deep pan with a basket until just smoking. In a wide, shallow bowl, mix half the vegetables and 1/3 of the lemon wedges. Sprinkle with 1 cup cornstarch and toss quickly with hands to coat. Toss into a large strainer with a handle and bat against hands to remove excess cornstarch. Drop the coated vegetables and lemons into the oil and cook until golden brown and crispy (about 2 minutes).
Remove to a plate lined with paper towels to drain. Immediately repeat with the 1/3 of the remaining lemons and all remaining vegetables. Season the hot fried foods with salt and serve immediately with fresh lemon wedges.