Smoked Chimichurri (Em Brasa)

Serves: Makes 1 medium jar
Time: 40 minutes, plus ageing time
Skill level: Intermediate
Equipment: Barbecue or open fire, coffee filter, small saucepan, kilner jar

• Bury your onion
• Place the whole onion, skin-on, directly into the hot embers — this is the rescoldo technique, cooking in residual heat rather than direct flame. How long it needs depends on how you plan to use the chimichurri. If you're ageing it for several days before eating, 20 minutes is enough — a little bite left in the onion works in its favour. If you want it ready to eat straight away, leave it until completely tender.
• Char your herbs
• Set aside roughly a quarter of the fresh herbs - coriander, parsley and oregano, stems and all - and chop. These uncharred herbs folded in at the end will add a brightness to the sauce. Take the remainder of the herbs and char them over a direct flame. You're looking for about 50% of the herb to be properly blackened. This is not an accident; the char is where the distinct smoky aromatic character comes from. Once charred, roughly chop all three bunches together.
• Smoke the butter
• Place the unsalted butter and whole garlic cloves into a small saucepan and set it directly over the hot coals. Once the butter has melted fully, use a pair of tongs to pick out one glowing coal from the fire and dip it into the butter for 3–4 seconds to properly enrobe it. Place it back on the barbecue to light on fire, then submerge it in the butter again. Return to the fire a second time, then submerge in the butter for a third and final time. Strain the entire contents of the melted butter through a coffee filter — this removes the coal particles and leaves you with a clean, deeply smoked butter.
• Bring everything together
• Place the chopped charred herbs and the freshly chopped herbs into a bowl. Take the outer skin off the onion, discard, and cut the onion into quarters, separating out it's layers, add to the bowl. Drizzle in the smoked butter a little at a time, tasting as you go — it is strong and you want balance, not dominance. Add approx. 400ml of olive oil, working it in gradually. Finish with a pinch of dried chilli flakes, season well, and stir to combine. Add a squeeze of lemon juice just before serving if you're pairing it with pork.
• Store and age
• Transfer everything to a clean kilner jar, top up with extra virgin olive oil, white wine vinegar, and place it on a shelf (keep it out of the fridge and freezer). The flavour develops over time — the oil, acid, and charred herbs continue to work together. It gets better after a few days, better again after a week. Matheus has kept his going for the better part of a year.