90 gmbutter, coarsely chopped3golden shallots, thinly sliced1garlic clove, finely chopped500 ml(2 cups) chicken stock150 gmdried split peas, rinsed500 gmfrozen peas, defrosted40 mlmalt vinegar, or to tasteOnion rings1small onion, thinly sliced and separated into ringsFor dusting:cornflourFor shallow-frying:vegetable oil
Heat 30gm butter in a saucepan over medium heat, add shallot and garlic, stir occasionally until tender (4-5 minutes). Add stock and dried split peas, bring to the boil, reduce heat to medium, simmer until tender (40-45 minutes). Add peas, simmer until tender (1-2 minutes), add vinegar, season to taste. Transfer solids to a food processor (reserve liquid), add remaining butter, pulse, adding a little reserved liquid, until coarsely puréed.
Dust onion rings in cornflour, shake off excess, season to taste. Heat 1cm oil in a deep frying pan over medium-high heat, add onion, stir occasionally until golden and crisp (1-2 minutes). Remove with a slotted spoon, drain on absorbent paper and serve scatterered over mushy peas.