Heat 1 tbsp butter or oil in a skillet over medium-high heat. Add sausage slices and cook until browned, 3–4 minutes. Remove and set aside. In the same pan, season shrimp with salt, pepper, garlic powder, and paprika. Sear until pink and charred, 2 minutes per side. Remove and set aside.
In a large pot, melt butter and olive oil. Add onion and red bell pepper; sauté for 3 minutes until soft. Add garlic and jalapeño; cook 1 minute. Stir in smoked paprika, cayenne, and Cajun seasoning. Pour in chicken broth and soy sauce, then simmer 5 minutes.
Lower heat. Stir in milk or half-and-half and shredded cheddar until melted. Add chili garlic paste or Sriracha for spice and depth.
Add noodles directly to the broth; cook for 3–4 minutes until tender. Stir occasionally so they soak up the creamy broth.
Divide noodles and broth into bowls. Top each with sausage, shrimp, green onions, and jalapeño slices. Add soft-boiled eggs if desired.
