Heat a wok over high heat until very hot; the metal will have a matte appearance and a drop of water flicked onto its surface should evaporate on contact. Add oil and heat until shimmering but not smoking.
Add 1 tbsp. fried shallots and garlic, cook 10 seconds, then add spinach and rice wine and toss to combine. Add fish sauce and chicken stock and continue stir-frying, tossing ingredients together, until spinach wilts, 30 seconds to 1 minute. Transfer to a bowl. Sprinkle with rest of fried shallots.
*Find nutty, slightly sweet Shaoxing rice wine at Asian markets and some liquor stores.