Vindaloo is known to be a fiery Indian dish, redolent with complex spices and vinegar tang underneath the heat. If you seed the serrano pepper, you’ll end up with a medium-spicy dish. For a mild dish, seed the serrano and reduce the amount of cayenne pepper to ¼ teaspoon. To go all in on the heat, leave the seeds in the serrano and use the full amount of cayenne pepper. If the finished dish ends up a little too spicy for you, serve with a cooling dollop of plain Greek yogurt.