Step 1

Look over your mussels and discard any that have cracked or broken shells. They all should be tightly closed, but if any open mussels don't close when you squeeze them gently with your fingers, discard those as well.

Step 2

Melt the butter in the olive oil in a deep, heavy-bottomed pot with a lid over medium heat.

Step 3

Add the leek and fennel, season with a pinch or two of salt, and cook until softened.

Step 4

Clear a space in the bottom of the pot and add the saffron, crumbling it with your fingers as you do, and lightly toast it before stirring it through the vegetables. Add the garlic and thyme, stir, and cook just until you can smell the garlic.

Step 5

Add the Pernod and vermouth or white wine, stir, and let cook for 2-3 minutes before adding the tomatoes. Reduce the heat to low, cover the pot, and simmer for 20-25 minutes.

Step 6

Add the mussels, stir, re-cover the pot, and cook for another 5-8 minutes or so, just until the mussels open (the timing will vary depending on the size of your mussels). Discard any mussels that don’t open.

Step 7

Stir the cream in off the heat, taste for seasoning, then spoon the mussels, vegetables, and sauce into a big, wide bowl – two, if you’re sharing. Sprinkle the fennel fronds on top, and serve with plenty of crusty bread.