Preheat oven to 325°F. Spread ½ cup sugar evenly in 2-quart saucepot. Pour the water over it and add the lemon juice. Without stirring, cook mixture at medium-high heat, occasionally swirling the pot to distribute the sugar. Watch carefully and when the melted sugar becomes an amber color (about 6–8 minutes), remove from heat and divide the mixture among 4 (6-ounce) ramekins. Place ramekins in a baking dish and heat a kettle of water for later use.

Next, add the cream and salt to the clean saucepot. Scrape the seeds from the inside of the vanilla bean into the cream. Add the blood orange juice, zest and cardamom and whisk to combine. Heat over low heat until the cream is hot but not boiling, then remove from heat.

In a separate bowl whisk the egg yolks and sugar together until smooth. After a minute, temper the eggs: Slowly pour the heated cream mixture into the egg mixture while continuously whisking.

Once all is combined, pour into the ramekins in equal portions over the caramel. Add enough hot water into the baking dish to come halfway up the sides of the ramekins and carefully place on the middle oven rack and bake for 30–40 minutes, or until set. Remove from oven and transfer ramekins to a cooling rack. When cool, transfer to the fridge and cool at least 2 hours before serving. (These can be made a day in advance, covered and refrigerated overnight.)

To serve, gently run a knife around the edges to loosen and turn each ramekin upside down onto a serving plate and tap to release the custard. Garnish with fresh or dehydrated blood orange rind and dried flowers.