Rinse the broccoli. Cut away most, but not all, of the stems. Chop into smallish pieces.

Peel the potato and chop into small cubes.

Rinse the leek. Chop off a 4-inch (10 cm) segment and slice crosswise.

Peel the garlic clove and chop in half.

Measure the water or stock into a large soup pot. Add the potato, leek slices and garlic. Add the salt and tarragon, and grind on some black pepper. Place over high heat.

When the pot boils, add the broccoli. Do not cover the pot. Turn down the heat and simmer for about 15 minutes, until all the veggies are tender.

Purée the soup using a counter-top or immersion blender. Squeeze in the juice of half a lemon. Taste and adjust the seasonings as necessary.

You now have the basic soup. Reheat gently just before serving, with one or more of the following variations: Stir 2-4 tbsp. crème fraîche or heavy cream into the soup as it is reheating. Garnish each bowl with the fresh herb of your choice.

Top the soup with homemade croutons: Preheat the oven to gasmark 7 (400 F, 210 C). Cube some bread, with or without the crusts. Place in a pie tin, drizzle with olive oil, sprinkle with salt and pepper and bake for 5-10 minutes, until the croutons are golden. Be careful, as the baking goes quickly and you don’t want the croutons to burn.

Finely grate a thumb of ginger. Stir into the soup as it is reheating. Top each bowl with a swirl of coconut milk. Garnish with fresh cilantro.

Stir 2 tbsp. olive oil into the soup after reheating. Top each bowl with a tablespoon of grated parmesan, and garnish with fresh basil leaves.

Thinly slice about two inches (5 cm) of spicy chorizo. Heat a tablespoon of olive oil to sizzling in a small frying pan. Add the chorizo slices and fry briefly on each side. Remove the slices and drain on a paper towel. Top each bowl with a few slices, and add some cilantro to garnish.