Step 1

Whisk ginger, soy sauce, raw sugar, lime juice, fish sauce, pepper, and garlic powder in a small bowl until sugar is dissolved. Whisking constantly, gradually add olive oil, then sesame oil. Transfer to a small resealable plastic bag and add steaks. Close bag, pressing out air, and turn steak to coat. Chill at least 6 hours and up to 12 hours.

Step 2

Prepare a grill for medium-high heat. (Alternatively, heat a grill pan over medium-high.) Remove steaks from marinade and pat dry. Season very lightly with salt. Grill, turning every 2 minutes, until lightly charred all over and an instant-read thermometer inserted into the thickest part of each steak registers 120° for medium-rare, 8–10 minutes total. Transfer to a cutting board and let rest at least 10 minutes before cutting into 1" pieces.

Step 3

Do Ahead: Steak can be grilled 1 day ahead. Let cool; cover and chill. Cut just before serving.

Step 4

Whisk lime juice, chili paste, peanut oil, fish sauce, sugar, honey, and garlic in a small bowl to combine. Taste and season with salt if desired.

Step 5

Do Ahead: Dressing can be made 1 day ahead. Cover and chill.

Step 6

Cook noodles in a small pot of boiling salted water until al dente. Drain and run under cold water to stop cooking. Toss with oil in a large bowl. Add mango, arugula, watercress, carrots, scallions, cabbage, tomatoes, and dressing and toss to coat. Season with salt if desired. Add steak, avocado, cilantro, basil, mint, coconut flakes, and ¼ cup peanuts. Gently toss just to combine.

Step 7

Divide salad among plates, piling as high as possible. Top with additional peanuts and serve with lime wedges for squeezing over.