If you will be toasting the pecans, pre-heat oven to 350 F.
Cut away tough broccoli stems and separate into florets.
Blanch the florets for 30 seconds by placing them into a pan of rapidly boiling water.
Drain quickly and place florets into a bowl of ice-cold water. Drain again and chill the broccoli in the refrigerator while making dressing.
Put sugar into a bowl, add the vinegar and whisk until mixed well together. Add soy sauce and wisk gently.
Add garlic and pepper. Stir well.
Add oil and mayonnaise and whisk until dressing is smooth.
Toss florets with onion and peppers. Add dressing and toss again to cover salad.
Arrange the pecans in a single layer on an ungreased baking sheet. Place in oven for 6 minutes, turning nuts few time to toast evenly.
Sprinkle pecans over the salad before serving.