Heat the oil and butter in a large saucepan over medium heat. Stir in the eschalots and saute for 2 to 3 minutes. Pour in the rice and stir well to coat, about 1 minute.
Next, pour in the wine and allow it to get absorbed by the rice, about 2 to 3 minutes. Then, stir in the broth 1/2 cup at a time, waiting until the rice absorbs each 1/2 cup before adding the next 1/2 cup. Repeat this until you have used all but 1/4 cup of broth, reserving this for later.
After about 20 minutes, the rice should be tender but firm. Turn off the heat. Stir in the remaining 1/4 cup of broth, the cheese, leftover lamb, garlic and artichoke hearts. Stir well to combine with the rice and serve on warm dinner plates.