I'm making ramen in couple days and cooked some pork belly in the pressure cooker. I have a Fissler pressure cooker and the top is interchangeable between a 8qt pot and a skillet, which I use when braising meats.
There's not much of a recipe, just braise the pork belly in a mixture of water and soy sauce with onion, garlic, black pepper corns and crushed red pepper.
Pork belly marinating in soy sauce.
I strained out the veggies and push the pulp through the mesh. This will be the basis of my ramen broth, along with miso and chicken stock.