In a large mixing bowl, combine the ground pork, chopped basil, minced garlic, and diced green onions. Next, add the fish sauce, sriracha, sugar, cornstarch, black pepper, and kosher salt. Use your hands to mix the ingredients until well combined, but don't overwork the mixture. You want to keep that juiciness intact!

With your hands, carefully shape the pork mixture into four even patties, each about ⅓-inch thick. Ensure they are uniform to cook evenly. Place them on a plate while you prepare the next steps.

While the patties are resting, grab a small bowl and whisk together the mayonnaise, chopped green onions, and sriracha until smooth. Make sure it’s well blended; this zesty sauce will be a star player in your burger!

Heat the toasted sesame oil in a large cast-iron skillet over medium heat. When the oil begins to shimmer, carefully add the pork patties. Cook them undisturbed for about 5 minutes until they're golden brown. Flip the patties and continue cooking until they reach an internal temperature of 160°F, about another 5 minutes. Use an instant-read thermometer for accuracy.

While the patties are cooking, you can toast the brioche buns on a separate skillet or grill until golden brown. A bit of fresh flavor is always a welcome addition to your meal!

Spread about 1 tablespoon of the sriracha mayo on the inside of each toasted bun (both top and bottom). Layer the bottom buns with the quick-pickled vegetables, chopped cilantro, and jalapeño slices (if you're feeling spicy). Place the cooked pork patty on top, and finish with the fresh cucumber slices. Cap it off with the top bun, mayo side down.

Repeat this assembly process with the remaining ingredients. Serve the banh mi burgers warm, garnished with extra pickled veggies or sriracha if desired.