Remove the artichokes from the marinade and set aside a few thick strips of the citrus zest. Use a food processor to pulse the artichokes and 2 tablespoons of oil from the artichoke jar to a chunky purée. Spoon the purée onto the crackers, along with a dollop of the romesco sauce. Thinly slice the zest. Top the purée with chopped nuts and sliced zest and season with salt.
Marinated Artichoke Hearts:
Place the bay leaf and lemon and orange zest on the inside of a sterilized jar then layer in the artichoke hearts, peppercorns and fennel seeds. Cover with olive oil and squeeze over the lemon juice. Press the contents down to ensure the artichokes are submerged. Seal with the lid and refrigerate for up to 6 months.
Blend all the ingredients except the olive oil in a food processor until finely chopped. Drizzle in the olive oil and pulse until combined.