Start by rinsing the white rice under cold water using a fine-mesh sieve until the water runs clear — this removes excess starch and helps achieve fluffy grains. Add the rinsed rice to a small pot with water (adjusting quantity based on servings) and a pinch of salt. Bring to a boil, then cover and reduce the heat to low. Let it simmer gently for about 15 minutes until tender. Once done, keep the rice covered off the heat for at least 10 minutes; this resting period lets the steam finish cooking the rice perfectly. While the rice cooks, prep your fresh ingredients. Wash and dry everything thoroughly. Peel and finely chop the garlic to release its aromatic punch. Zest the lime carefully to capture its fragrant oils, then quarter it (for larger servings, zest one lime and quarter two). Trim the cucumber, halve it lengthwise, and slice into delicate half-moon shapes to provide a refreshing crispness. Peel and dice the onion into medium pieces for caramelizing, and grate the carrots to add a subtle sweetness and texture. To create the pickled cucumber, combine the sliced cucumber with juice from half the lime, a touch of sugar, and a pinch of salt in a medium bowl. This quick pickling brightens the cucumbers and adds a tangy crunch. In a small bowl, mix the mayonnaise with a pinch of garlic, a splash of lime juice, and your desired amount of sriracha for that spicy creamy sauce — season with salt and pepper to taste. Heat a drizzle of oil in a large pan over medium-high heat. Add the diced onion and cook, stirring occasionally, until softened and slightly caramelized, about 4 to 5 minutes. Add the ground beef, remaining garlic, and sugar to the pan. Break the meat apart with your spoon, cooking until it’s browned and cooked through, another 4 to 5 minutes. Stir in the soy sauce to bring a savory depth of flavor. Turn off the heat and adjust seasoning with salt and pepper as desired. Fluff the cooked rice gently with a fork to separate the grains, then stir in the fragrant lime zest and a tablespoon of butter to infuse the rice with creamy richness. To assemble, divide the lime butter rice among bowls. Arrange the savory beef, grated carrot, and pickled cucumber attractively on top. Finish with a fresh squeeze of lime juice to brighten all the flavors and finish with a generous drizzle of the spicy sriracha mayo. Enjoy your vibrant and comforting Beef Banh Mi Bowl!