Step 1Heat the olive oil in a medium skillet over medium-high heat. Add shiitakes and cook, stirring or shaking the pan constantly, until tender. Drizzle with 1 teaspoon soy sauce and continue cooking until almost crisp. Set aside.
Step 2In a small bowl, whisk together the remaining soy sauce with the lemon juice and pepper to taste. Add the hazelnut oil and whisk until emulsified. Taste and adjust the seasoning.
Step 3Place the watercress in a large salad bowl. Cut the avocado into quarters lengthwise, remove the pit and cut crosswise into thin slices. Slide the fruit off the skin into the bowl. Add the peppers and shiitakes and toss well. Add just enough dressing to coat and toss again. Divide the mixture among serving plates and sprinkle with almonds.