Boil the noodles: Bring a medium pot of water to a boil. Add ramen and cook 1–2 minutes less than package directions.
You want them just shy of tender so they don’t get mushy later. Reserve 1/2 cup of cooking water, then drain.
Start the sauce: While the noodles cook, heat a large skillet over medium heat. Add the butter and let it melt, swirling occasionally.
Toast the garlic: Add the minced garlic to the butter.
Cook 45–60 seconds, stirring constantly, until fragrant and just turning golden at the edges. Do not let it brown deeply or it will taste bitter.
Season the base: Stir in soy sauce and brown sugar. Let it bubble for 10–15 seconds to dissolve the sugar and marry the flavors.
Add the noodles: Toss the drained ramen straight into the skillet. Add a splash of reserved cooking water (start with 2–3 tablespoons) and use tongs to coat the noodles in the sauce.
Finish with aromatics: Drizzle in sesame oil, add lemon juice or rice vinegar, and sprinkle in red pepper flakes if using.
Toss until glossy and evenly coated, adding more cooking water a tablespoon at a time if it looks dry.
Season and serve: Taste and adjust with a pinch of salt, a crack of black pepper, or an extra squeeze of lemon. Fold in green onions. Plate immediately while hot.
Optional upgrades: Top with a jammy egg, sautéed mushrooms, or a handful of baby spinach that will wilt in the heat.
For protein, stir in cooked chicken, tofu, or shrimp in the last minute to warm through.