Miso-Glazed Cod with Bok Choy

Why this works for founders

Cod is one of the lowest-mercury fish available and provides solid lean protein without the heavy fat load of red meat. Miso is fermented soy, contributing glycine (an amino acid linked in several controlled trials to improved sleep onset). Bok choy adds folate and vitamin K with very few calories. Light dinner, deep sleep.

Ingredients (2 servings)

• 2 cod fillets (about 150g each)
• 2 tbsp white miso paste
• 1 tbsp mirin
• 1 tbsp soy sauce
• 1 tsp honey
• 1 tsp grated ginger
• 4 heads baby bok choy, halved lengthwise
• 1 tbsp sesame oil
• 1 tbsp neutral oil
• 2 cloves garlic, minced
• Sesame seeds, sliced spring onion to serve
• Cooked brown or jasmine rice to serve

Steps

1. Mix miso, mirin, soy, honey, ginger in a small bowl.
2. Pat cod dry. Brush with miso glaze. Let sit 10 min.
3. Heat oven to 220°C / 425°F. Line a sheet pan.
4. Place cod on the pan. Roast 10–12 min until flaky.
5. Meanwhile heat sesame oil and neutral oil in a pan over high. Add bok choy cut-side down, 2 min until charred. Add garlic, splash of water, cover 2 min.
6. Plate over rice. Top with sesame seeds and spring onion.

Macros per serving (approx)

• Calories: 420
• Protein: 36g
• Fat: 12g
• Carbs: 42g

Founder note

Light early dinner (6–7pm) gives your digestive system enough downtime before bed that you'll see better deep-sleep numbers on whatever tracker you wear. Heavy late dinners reliably tank deep sleep.

The deeper logic

Cod (Atlantic or Pacific) is one of the leanest commonly available
fish at roughly 1 g fat per 100 g. The protein density is 20 g per
100 g, with a complete amino acid profile and a particularly high
content of taurine and glycine. Glycine is the precursor to
glutathione (the body's central antioxidant) and a known modulator
of GABA-A receptor activity — a small amount of glycine before
bed has shown modest improvements in sleep onset and architecture
in several small trials.

Miso is a fermented soybean paste with a tradition going back
roughly 1,300 years in Japan. The fermentation (Aspergillus oryzae,
typically) produces glutamate, several B vitamins (notably B12 in
trace amounts), and probiotic bacteria — although the cooking heat
in this recipe will kill most of the bacteria. The umami
contribution from miso glutamate is significant; cod with a miso
glaze tastes meaningfully different from cod with just salt.

Bok choy is one of the higher-magnesium leafy greens (20 mg per
100 g raw) and is part of the brassica family — contributing
sulforaphane on chopping and chewing. The mineral profile of bok
choy plus the magnesium and tryptophan profile of cod makes this
a sleep-supportive dinner without being a heavy one.

Why this is a sleep-night dinner

The combination is unusual in the founder kit: high protein, very
low fat, sleep-supportive amino acid profile, modest portion size.
The 6 to 7 pm dinner finishes digestion by 10 pm, which means
sleep onset arrives without competing with active digestion.

A heavier, fattier dinner (lamb, steak, salmon) at 8 pm pushes
digestion into the 11 pm to 1 am window — exactly when deep
sleep should be dominant. The cod dinner is the move on the
nights you need a clean sleep.

Substitutions

• No cod: halibut, haddock, hake. Any white-fleshed lean
  fish works. Salmon is too fatty for this specific use case.
• No miso: soy sauce plus mirin (Japanese cooking wine) for a
  similar umami-and-sweet profile, or skip and use just soy
  sauce.
• No bok choy: baby kale, broccoli florets, or spinach. Each
  has slightly different cook times; bok choy is the closest in
  cook profile.
• No mirin: sake plus 1 teaspoon of sugar, or skip the mirin
  and use a touch more honey.

Storage detail

Cooked fish holds 2 days refrigerated and reheats acceptably but
not well. The texture firms up; the flavor stays but is muted.
The miso glaze in particular is best fresh.

If you must batch-cook, make the miso paste in advance (holds 5
days refrigerated) and cook the cod the night you eat it.

Common mistakes

• Overcooking the cod. The fish goes from translucent to flaky to
  dry in about 3 minutes. Pull when the center is just opaque;
  carryover finishes the cook.
• Not patting the fish dry before glazing. Moisture on the surface
  prevents the glaze from caramelizing under the broiler. Pat
  dry with paper towels; glaze; broil.
• Adding too much miso. The miso flavor is strong; one tablespoon
  per fillet is the upper bound. Some recipes call for two
  tablespoons; the dish reads salty-overwhelming at that ratio.

The cod-and-miso dinner is the sleep-night meal in the founder
kit. Twenty minutes total. A real dinner that does not sabotage
the night.