Chinese Tofu Peanut Stir-Fry

Ingredients:
12 oz firm tofu, diced
1/2 cup peanuts
2 tbsp soy sauce
1 tbsp sesame oil
2 cloves garlic, minced
1 inch ginger, minced
1 red bell pepper, sliced
1 green bell pepper, sliced
1/2 cup broccoli florets
1/4 cup water
2 tbsp cornstarch
2 tbsp vegetable oil