leek toasts with blue cheese

INGREDIENTS

• 1 1/2 pounds leeks (about 3 big leeks), lengthwise and white and pale green parts sliced 1/4-inch thick (about 3 generous cups of slices)
• 2 tablespoons unsalted butter
• 1 tablespoon olive oil, plus extra for brushing toasts
• Coarse salt
• Freshly ground black pepper
• 6 medium-sized or 12 baguette-sized 1/2-inch slices of bread of your choice (I used a light sourdough)
• 2 ounces blue cheese, crumbled (a soft or crumbly goat cheese would also work)
• Few drops of lemon juice (optional)