01 - In a medium mixing bowl, whisk together the soy sauce, rice vinegar, maple syrup, minced garlic, chili flakes, and smoked paprika until well combined.
02 - Add the tempeh cubes to the marinade and toss to coat evenly. Let sit for at least 10 minutes to absorb the flavors.
03 - In a shallow dish, combine the cornstarch, panko breadcrumbs, kosher salt, and black pepper. Mix thoroughly to distribute the seasoning evenly.
04 - Remove the tempeh cubes from the marinade, shaking off any excess liquid. Dredge each cube in the breadcrumb mixture, pressing gently to ensure an even, adherent coating on all sides.
05 - Pour the vegetable oil into a deep saucepan or heavy-bottomed skillet and heat to 340°F (170°C). Use a thermometer to maintain a consistent frying temperature.
06 - Carefully lower the coated tempeh nuggets into the hot oil in small batches. Fry for 3 to 4 minutes, turning occasionally, until golden brown and crispy on all sides. Avoid overcrowding the pan to maintain oil temperature.
07 - Using a slotted spoon or tongs, transfer the fried nuggets to a plate lined with paper towels. Allow excess oil to drain completely.
08 - Arrange the hot crispy nuggets on a serving plate. Garnish with sliced green onion, thin red chili slices, and fresh cilantro leaves. Serve alongside sweet chili sauce or vegan mayonnaise for dipping.