Preheat the oven to <temperature>180<unit>°C</unit></temperature>

Peel <quantity>12</quantity> baby onions

Cut them in half crosswise

Transfer to a bowl and add the zest of <quantity>½</quantity> a lemon

Add salt to taste and <quantity>2<unit>tbsp</unit></quantity> of extra virgin olive oil

Toss to coat all the onions

Transfer the onions to a pan with the wider part up and top with <quantity>3</quantity> sprigs of thyme

Bake the onions for at least 25m until tender and deep golden brown

Trim, half and peel <quantity>1</quantity> medium onion

Preheat a cast-iron skillet over high heat and add the onion. Char on both sides until deep brown

Transfer the onion to a saucepan, cover with <quantity>200<unit>ml</unit></quantity> of water and let it cook on low heat for 15-20m to extract the flavors

Fill ¼ of a small saucepan with water. Bring it to a gentle simmer over low heat

Add <quantity>3</quantity> egg yolks to a large bowl and whisk. Squeeze <quantity>1<unit>tsp</unit></quantity> of fresh lemon juice while whisking. Season with salt to taste

Place the bowl over the saucepan. Whisk the yolk until it starts to thicken. If the water starts boiling, turn off the heat and turn it back on when the steam nearly subsides

Add <quantity>250<unit>g</unit></quantity> of cubed cultured butter, in batches, while whisking. Continue until the mixture turns into a velvety sauce. Make sure to fully emulsify a batch of the butter before adding another

Remove from heat. The hollandaise sauce is ready. Reserve

Remove the onions from the oven. The caramelized baby onions are ready. Reserve

Remove the charred onion broth from heat, discard the onion and add <quantity>2<unit>tbsp</unit></quantity> of oyster sauce. Stir to combine and reserve

Season both sides of <quantity>4</quantity> halibut fillets with salt to taste

Fill a pan with <quantity>200<unit>ml</unit></quantity> of water and add <quantity>50<unit>ml</unit></quantity> of extra virgin olive oil

Turn the heat on to high and place the halibut fillets in the pan, leaving some space between them

When the water starts to boil, reduce the heat to low and cover with a lid for 1m to precook

Tilt the pan and baste the fillets with the pan liquid for 4m until they are opaque and cooked through

Check if the fillets are done by poking them with a cake tester, you should find little no resistence. The braised fish fillet is ready

Plate a portion of the Caramelized Baby Onions

Plate a Braised Fish Fillet and a portion of the Hollandaise Sauce on the side

Drizzle the onions with a portion of the charred onion broth

Garnish the fish with dill to taste. The braised fish with hollandaise sauce is ready

Tasty, rich and moist! Enjoy!