Season pounded pork chops with salt and pepper, then dust with flour.
Dip pork chops in beaten egg, then coat with panko.
Fry pork chops in a skillet with hot oil until golden brown, about 5-6 minutes per side.
Drain fried pork on paper towels and slice into pieces.
In a saucepan, heat dashi, soy sauce, mirin, and sugar until boiling, then remove from heat.
In a small skillet, simmer onion slices in 1/4 of the broth.
Add tonkatsu pieces to the skillet, pour beaten egg over, cover, and cook until the egg sets.
Serve tonkatsu and onion mixture over steamed rice in a large bowl. Repeat for additional servings.