Korean-Style Noodle Soup with Shrimp

This is a simplified, not-too-spicy version of haemul jjampong, a fiery Korean seafood and noodle soup. Gochujang, or Korean chili paste, gives the broth a bright red hue, as well as chili heat and a solid dose of umami. Look for gochujang in red bottles or tubs in the international aisle of the grocery store or in Asian markets. We cook the starchy udon noodles directly in the broth to add body to the soup, which also makes this a simple one-pot dinner that can be on the table in about half an hour.