Instructions
Follow the steps and taste along the way.
Prepare the vegetables
Preheat the oven to 220 °C. Break the cauliflower into florets about 3 cm wide. Cut the onion into wedges and roughly chop the garlic.
Roast the vegetables
Spread the cauliflower, onion, and garlic on a baking sheet, drizzle with olive oil, and season with salt. Roast for 22 to 25 minutes, turning the vegetables after 12 minutes. The cauliflower should be tender and golden brown at the edges, not burnt.
Heat the stock
While the vegetables finish roasting, heat the vegetable stock in a small saucepan until hot, but not at a vigorous boil.
Blend the sauce
Transfer the roasted vegetables to a blender. Add the hot stock, capers, Dijon mustard, and lemon juice. Blend until smooth; if the sauce is too thick, blend in another 15 ml of hot water.
Finish and season
Pour the sauce into a saucepan and warm over low heat for 2 minutes, stirring occasionally, without letting it boil vigorously. Stir in the chopped parsley and black pepper. Taste; the lemon adds fresh acidity and the capers saltiness, so add more salt only if the sauce tastes bland.
