Method

Warm a heavy-based saucepan large enough to contain the 4 chicken breasts over medium heat. Add the olive oil and then the butter (this prevents the butter from burning). As soon as the butter starts forming tiny bubbles, add the chicken breasts. Fry the chicken slowly, not turning too often, until golden and still firm. Slice the chicken breasts at a slant on the diagonal and keep to one side. Cover and keep warm.

Sauce

Warm the butter and the lemon juice in a small saucepan until the butter has melted and the sauce is just about bubbling. Remove from the heat and, using a whisk, very quickly whisk in the egg yolk while the sauce is still very hot. Continue whisking until the sauce turns an opaque yellow and has a coating consistency. If the sauce is not warm enough the egg yolk will not cook, so you might need to return it to the heat for 1 minute, whisking all the while. You will know the egg is cooked sufficiently by the opaque colour as well as the coating quality of the sauce. If the sauce starts to curdle at this point, quickly remove it and whisk in 1 Tbsp (15 ml) ice-cold water. Add the lemon zest and keep to one side until you are ready to serve. Do not reheat the sauce.

Arrange the sliced chicken breasts on serving plates or on a platter with the sauce scooped over liberally and the papaya scattered over. Serve with a crisp salad and basmati rice or a light, not creamy, potato or butternut purée.