In a large bowl, whisk together the ricotta, cream, honey, orange zest and vanilla seeds until light and fluffy. Cover and refrigerate for 30 minutes.
Heat the grill to high. Brush the nectarines with oil and put on grill for a few minutes on each side, just to soften and heat through.
Put some of the ricotta onto each serving plate. Top with nectarines and garnish with toasted sliced almonds and mint sprigs.