In a medium saucepan, heat the stock and saffron together to steep the saffron threads, about 5 minutes.
In a medium pot, melt the butter over medium heat. Add the pasta and brown until nutty and fragrant. Stir in the rice, then stir in the tomato and saffron stock and bring to a boil. Lower the heat, cover and simmer until tender, 16 to 18 minutes.
Meanwhile, in a dutch oven with a tight-fitting lid, heat the EVOO, 2 turns of the pan, over medium-high heat. Add the chorizo and brown for a couple of minutes. Stir in the corn, chile pepper and garlic.
Add the beer (or wine) and clams; scatter the cilantro (or parsley) on top. Cover the pan and cook until the clams open, 7 to 10 minutes. Discard any unopened clams. Stir to combine the sauce. Serve the pasta and rice in shallow bowls, topped with the clams, corn and sauce.