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