Add the sichuan peppercorns to a dry pan over medium heat. Cook, shaking the pan regularly until the peppercorns start to toast. Transfer to a mortar and pestle (or an electric spice grinder) and grind into a powder.
Bring a pot of water to a boil. Add the udon noodles and cook until al dente.* Drain and rinse with cold water.
Combine the soy sauce, rice vinegar, sesame oil, agave, sesame seeds, garlic, ginger and sichuan powder (to taste)** to a bowl. Stir to combine.
Combine the cold noodles and sauce in a bowl and toss to combine.
Transfer to plates and top with cabbage, green onions and more sesame seeds. If there is any leftover sauce in the bottom of the noodle bowl, drizzle it over the noodles.
*Be sure not to overcook the noodles, they will cook quickly.
**I added about 1 1/2 teaspoons of the powder and these noodles had a good amount of heat. Start with less and add more to taste.
FOR LEFTOVERS: These makes great leftovers! You can keep the veggies and the noodles in the same bowl, but the cabbage will continue to soften as it sits in the fridge, so just keep that in mind.
Calories: 307kcal, Carbohydrates: 48g, Protein: 11g, Fat: 9g, Saturated Fat: 1g, Polyunsaturated Fat: 3g, Monounsaturated Fat: 3g, Sodium: 1271mg, Potassium: 219mg, Fiber: 5g, Sugar: 11g, Iron: 1mg