Set a large pot of salted water on to boil. Trim the Brussels sprouts and halve. Peel the carrots and cut into 2 inch long sticks. Thinly slice the scallions. When water comes to a boil, add udon noodles and cook until al dente; about 6 to 8 minutes. Rinse noodles under cold water and toss with 2 tsp vegetable oil.
In a large nonstick skillet, toast the peanuts over medium-low heat, about 4 to 5 minutes. Cool and roughly chop. Halve the lime. In a blender combine, juice from the lime, garlic, almond butter, tamari, as much of the chili garlic sauce as you’d like, maple syrup, and ¼ cup water. Blend on high until smooth. Add half of the peanuts, season with salt and blend once more.
Heat the same skillet over medium high heat with 2 tbsp vegetable oil. Add the Brussels sprouts and cook, shaking the pan often, until charred in places; about 3 to 5 minutes. Add ½ cup water to create some steam, reduce heat to medium, and continue cooking until sprouts are bright green and just tender, about 3 to 5 minutes more.
Add the carrots and continue to cook until tender, about 4 to 6 minutes. Reduce heat again to low, and add edamame, almond butter sauce, and ¾ cup water. Toss vegetables to combine, reduce heat, and bring sauce to a simmer.
Add the cooked udon to the skillet, taste and season, and toss to combine. Stir in half of the chopped scallion.
Divide spicy almond butter udon between large plates and top with remaining scallion and chopped peanuts. Dig in!