Bring a pot of water to a boil. Add udon noodles and cook according to package instructions until tender but chewy, about 8-10 minutes. Drain and set aside.
In a large skillet, heat sesame oil over medium heat. Add minced garlic and sauté until fragrant, about 1 minute.
Stir in gochujang paste and soy sauce, cooking for 1-2 minutes until blended and aromatic.
Lower heat and pour in heavy cream. Stir continuously until the sauce is smooth and heated through, about 2-3 minutes.
Add the cooked udon noodles to the skillet. Toss gently to coat the noodles evenly with the creamy gochujang sauce.
Transfer noodles to a shallow bowl, twirling them into a neat mound.
Garnish with sliced green onions and sprinkle toasted sesame seeds on top before serving.