For the scallop ravioli with seared scallops, place the flour and eggs in a food processor and blend until it resembles fine breadcrumbs.
Lightly flour a clean work surface. Remove the ingredients from the food processor and bring together to form a smooth dough. Wrap in cling film and place in the fridge for at least 20 minutes.
Meanwhile, make a scallop mousse for the ravioli filling. Add two scallops and the cream to a food processor. Season with salt and freshly ground black pepper and add the lemon juice. Blend until smooth then stir in the chives. Set aside.
Divide the rested pasta dough into four and pass through a pasta machine. Start with the pasta machine at its widest setting and pass the dough through the rollers. Do not fold but repeat this process, decreasing the roller setting down grade by grade with each pass, until you reach the thinnest setting. Roll out two sheets of pasta (approximately 12x25cm/5x10in).
Lay the pasta sheets out on a work surface, dust with semolina and trim to form two equally sized rectangles. Any excess pasta can be wrapped in cling film and refrigerated for a few days or frozen for later use.
Place a spoonful of the scallop mousse in one corner of the pasta sheet approximately 2½cm/1in from the edge. Repeat at 6cm/2½in intervals until you have eight small mounds of mousse on the pasta sheet.
Brush with egg around the edge of the mounds and lay the second pasta sheet on top. Use your fingers to gently press around the mounds to remove any excess air and help the pasta sheets adhere. Use a pastry cutter to cut out 6cm/2½in rounds of ravioli.
For the white wine sauce, heat a medium frying pan and add the butter. Once melted add the shallots and fry for 2-3 minutes. Add the garlic and cook for a further two minutes. Add the wine and stock, then bring to the boil. Cook until the volume of the liquid has reduced by half. Remove from the heat and stir through the cream.
Place another frying pan over a medium heat and add a knob of butter. Once the butter has melted, add the samphire and sea purslane. Fry for 2-3 minutes, or until the samphire is tender.
Fill a large saucepan with boiling, salted water. Place the ravioli in the water and cook over a medium heat for 1-2 minutes. Drain and set aside.
Meanwhile, heat the remaining butter in a frying pan. Once the butter is foaming, add the remaining scallops and cook on each side for approximately a minute, or until golden-brown on both sides and just cooked through.
Just before serving, add the tomato and picked chervil to the white wine sauce.
To serve, place the ravioli on serving plates along with a seared scallop each, scatter the samphire and sea purslane over and finish with the cream sauce.