Udon with Tofu and Asian Greens

INGREDIENTS

• Kosher salt and freshly ground pepper
• 4 tablespoons roasted peanut oil, or 3 tablespoons sesame oil mixed with 1 tablespoon vegetable oil
• Large pinch of red pepper flakes
• 1 8-ounce package udon noodles
• 1 12-ounce package firm tofu, cut into 12 pieces
• 1 bunch scallions, thinly sliced diagonally
• Pinch of sugar
• 3 tablespoons soy sauce
• 1 11-ounce package Asian cooking greens or baby spinach