After trying a lot of authentic Pad Thai recipes, and making many adjustments, I find this to come closet to the restaurant flavors I like. I personally prefer Pad Thai that's more moist and flavorful than the drier style ones.
Start by soaking the flat rice noodles in slightly hot water for 30-50 minutes. Lets prepare the other ingredients while soaking.
Cut the firm tofu into matchsticks cuts (thin strips about 1 inch long). Fry the tofu in 1 tbsp peanut oil until golden on all sides. Set aside.
Add salt to egg and gently stir.
Prepare the sauce. Combine fish sauce, sugar, soy sauce, Thai Style Chili Sauce, Tamarind juice concentrate, ketchup, and chili pepper. Set aside.
Heat up 1 tbsp peanut oil over medium-high fire; add garlic, ginger, and crushed red pepper.
Once garlic begin to brown, add cabbage, stir until soften.
Add the prepared sauce.
Add the flat rice noodles, stirring quickly to prevent from sticking. Taste the noodles to check firmness. Noodles should be heavier in taste at the moment, but if it's not soft enough, add a little water and cook a bit longer.
Put noodles to one side, crack egg into pan, and in about 20 seconds, scramble and fold into noodles.
Add shrimp, stir for 30 seconds.
Add bean sprouts, green onion, firm tofu, and peanuts.
When shrimps are pink on both sides, remove from fire.