A really good green smoothie

Its first advantage is simple: it gets down a quantity of green vegetables you would rarely eat as they are. A cup of raw spinach in a glass is a whole portion swallowed without thinking about it, fibre included — unlike a centrifuged juice, a smoothie keeps the whole plant. Add to that the vitamin C of the citrus and pineapple, and the satisfying quality of the flax seeds. The point to watch is sugar: three dates plus two bananas plus an orange is a lot of fruit for a single glass. Better to make it a breakfast than a drink alongside a meal.

It all depends on the result you want. Water remains the most neutral base, the one that lets the fruit speak without adding anything. Citrus juice, as here, brings acidity and sugar: it carries the green vegetables, but it counts in the balance of the glass. Plant drinks — almond, oat, coconut — give creaminess and a little fat, which slows down how sugars are taken up and prolongs satiety. Coconut water, finally, brings minerals and a light sweetness. Allow 150 to 250 ml for a large glass, adjusting as you go rather than all at once.

The golden rule is to go gently: half a teaspoon is plenty for one glass, and a whole spoonful dominates everything. Its marine taste works well with acidity — pineapple, lemon, orange — and far less with red berries, which turn brown. Add it at the end of blending, for a few seconds only, to stop the blender warming the mixture. And serve immediately: spirulina oxidises quickly and the bright green of the first moment turns dull after half an hour.

Morning or early in the day, rather than evening: spirulina has a fairly energising effect on many people. Another useful marker is to pair it with a source of vitamin C — here, the orange and pineapple do the job perfectly — since that vitamin improves the uptake of the plant iron it contains. Finally, if you are new to it, start with small amounts over several days: too brutal an introduction sometimes causes digestive discomfort that is in no way inevitable.