For sauce, whisk soy sauce, water, Hoisin, cornstarch, sesame oil, and Sriracha sauce together in a small bowl until well combined; set aside.
For noodles, bring a large pot of water to a boil over medium heat. Add ramen noodles and cook until al dente according to package directions, about 3 minutes. Drain and set aside.
Meanwhile, heat sesame oil in a large skillet. Add beaten eggs, and scramble just until set, 1 to 2 minutes. Remove to a plate, and set aside.
Add kielbasa to the same skillet, and cook until browned on all sides, 3 to 4 minutes. Remove to the plate with the eggs.
Add bell pepper and onion to the skillet, and stirring occasionally, cook until starting to become tender but still partially crisp, 3 to 4 minutes. Add garlic and cook until fragrant, about 30 seconds. Transfer to the plate with the kielbasa-eggs.
Heat avocado oil in the same skillet over medium heat. Add drained noodles, and fry for 2 to 3 minutes. Fold kielbasa-veggie-egg mixture into noodles, stirring and separating until well combined.
Give the sauce a good stir, pour into the skillet, toss and cook until the sauce starts to slightly thicken, and all is well coated, 3 to 4 minutes.
