Little Gem Salad with Grapes, Blue Cheese & Walnut - Another Pantry

Ingredients

• 250g black grapes
• 15g butter
• 75g walnuts, roughly chopped
• 1 tsp caster sugar
• 6 Little Gem lettuces, each cut into 4 wedges through the stem
• 1 large, not-too-ripe pear, quartered, cored and sliced
• A few sprigs of tarragon or a few chives, chopped
• Salt and pepper
• 150g blue cheese such as Stilton, Stichelton, Cashel Blue or Gorgonzola
• 3 tbsp Greek yogurt or soured cream
• 2½ tbsp white wine vinegar
• 6 tbsp olive oil