Season the short ribs with salt and pepper.

Heat the olive oil in a large Dutch oven or heavy bottomed pot, over medium-high heat, until shimmering. Add the short ribs, working in batches if necessary, and brown on all sides, about 2-3 minutes per side. Remove and reserve.

Add the onions and sauté until beginning to brown, about 3-4 minutes. Stir in the garlic, ginger and red pepper flakes. Cook until fragrant, about 1 minute.

Pour in the mirin to deglaze the pot. Using a wooden spoon, scrape all the browned bits from the bottom of the pan. Cook until the mirin has reduced to half.

Pour the soy sauce and chicken broth. Bring to a boil. Once boiling, add the short ribs (and juices) back into the pot.

Cover, lower the heat to a simmer, and cook for 1.5 to 2 hours or until the short ribs are very tender. You can skim off the fat that rises to the top.

Remove the short ribs onto a cutting board and shred into large chunks.

Add the water to the broth. Taste and adjust seasoning if needed.

Bring a large saucepan full of water to a boil, over high heat. Add the ramen noodles and cook according to package directions. Drain and run under cold water to stop cooking.

Assemble the bowls by placing the noodles and meat, and pouring the broth. Then, drizzle them with sesame oil and top with the desired toppings.

Serve immediately!