Heat the butter in a medium saucepan over medium heat. Once it's melted, whisk in the flour. Continue cooking, whisking constantly, for about 2 minutes, or until lightly browned. Pour in the milk and beer, add the sriracha and whisk until smooth; bring to a simmer. Cook until the sauce is thick, about 3-5 minutes. Remove from heat and add the cheese a handful at a time, whisking until melted. Season with salt to taste. Transfer the cheese sauce to a bowl and swirl sriracha over the top, then garnish with green onions.
Craving more veg-friendly recipes? Shop our collection of vegetarian and vegan cookbooks, including our new Vegan Thanksgiving and Vegan Christmas cookbooks!