Prepare ingredients and rice water: Measure rice and rinse it under cold water until the rinse runs mostly clear—this removes excess surface starch so the cooked rice is fluffy, not gluey. Bring 3 cups (720 ml) water to a simmer in a medium saucepan; keep covered off heat until ready.

Sweat half the onion: Finely chop half the onion (≈100 g). In a small skillet over medium heat, add 1 teaspoon oil and 1 tablespoon butter and sauté the chopped onion with a pinch of salt until translucent, about 4–5 minutes. Sweating the onion removes the raw edge and releases sweet aromatics so they integrate smoothly into the meat mixture—cool to room temperature before mixing.

Make the meat mixture: Put the ground beef in a bowl. Add the cooled sweat onion, 1 large egg, 1/4 cup (30 g) flour, 2 minced garlic cloves, 1 teaspoon kosher salt, and 3/4 teaspoon freshly ground black pepper. Gently mix with your hands or a fork just until combined—overworking toughens the meat. The egg and flour bind the patties; the sautéed onion adds moisture and sweetness without making the mixture watery.

Portion and rest: Divide the meat into eight equal portions (about 2.25–2.5 oz / 63–70 g each) and shape into slightly flattened oval patties about 1/2" (1.3 cm) thick. Arrange them on a tray, cover, and chill 10–15 minutes. Chilling firms the mixture so patties hold together and form a better crust when they hit the pan.

Start the rice: Melt 1 tablespoon butter in the medium saucepan over medium heat. Add 1 minced garlic clove and the rinsed rice; stir and cook for 60–90 seconds to lightly toast the rice and infuse it with garlic flavor—this step adds a subtle nutty depth. Add the 3 cups simmering water and 1/2 teaspoon salt, bring to a gentle boil, then lower heat to a bare simmer, cover tightly and cook undisturbed 15–18 minutes (until water is absorbed). Remove from heat and let rest, covered, for 10 minutes to finish steaming.

Caramelize the remaining onion: While the rice cooks, heat a clean skillet over medium-low and add 1 tablespoon butter. Add the thinly sliced onion and a pinch of salt. Cook slowly, stirring occasionally, for 12–18 minutes until deep golden brown—lower heat if the edges brown too quickly. Add a splash (1–2 tablespoons) of water to deglaze and coax up brown bits. Caramelization creates sweet, savory flavor and a glossy texture that contrasts beautifully with the savory beef.

Dust patties and heat the pan: Lightly dust each chilled patty with the remaining 2 tablespoons flour—this small coating promotes a golden, crisp crust. Heat a large skillet over medium-high until hot, then add 2 tablespoons vegetable oil and swirl to coat. A properly hot pan is essential to create Maillard browning (the flavorful crust) without drying the interior.

Sear the patties: Add patties without crowding (work in batches if needed). Sear undisturbed 3–4 minutes until a deep brown crust forms, flip, and cook 3 minutes on the second side. During the last 60–90 seconds, add the remaining 2 tablespoons butter to the pan and tilt it toward you; use a spoon to baste the patties with the melted butter—this finishes them with gloss and rich flavor while preventing drying. If you’re unsure of doneness, a quick check with an instant-read thermometer should read about 160°F (71°C) for ground beef.

Rest the patties: Transfer finished patties to a warm plate and let rest for 3–5 minutes—resting lets juices redistribute and avoids losing them when cutting or serving.

Finish the rice and plate: Fluff the garlic rice with a fork and stir in the remaining tablespoon of butter to make it glossy and rich. Taste and adjust seasoning with salt and pepper. Spoon rice onto plates, top with two patties per serving, crown with a generous nest of caramelized onions, and sprinkle with chopped parsley if using. The contrast of crisp crust, tender interior, silky rice, and sweet onions is the goal.