Chicken Pad Thai

Chicken Pad Thai.

8 oz. Thai rice noodles (or enough for 2 people), linguini-width, available at Asian/Chinese stores
1 to 1 1/2 cups raw chicken breast or thigh meat, sliced
Marinade for Chicken: 1 tsp. cornstarch dissolved in 3 Tbsp. soy sauce
4 cloves garlic, minced
optional: 1-2 fresh red chilies, minced
3 cups fresh bean sprouts
3 spring (green) onions, sliced
1/2 cup fresh coriander/cilantro
1/3 cup crushed or roughly chopped peanuts (or other nuts, such as cashews)
1/4 cup chicken stock
1/8 tsp. ground white pepper
vegetable oil for stir-frying, and wedges of lime
PAD THAI SAUCE:
3/4 Tbsp. tamarind paste dissolved in 1/4 cup warm water (look for tamarind at Asian/Chinese or Indian food stores)
2 Tbsp. fish sauce, + more to taste
1-3 tsp. chili sauce, or substitute 1/2 tsp. or more dried crushed chili or cayenne, to taste
3 Tbsp. brown sugar