This is a great appetizer paired with roasted red peppers and Rustica baguettes

4 large flat-topped yellow onions or the sweetest onion in-season, cut into 1-inch-thick slices
¼ cup extra virgin olive oil

4 ounces blue cheese
¼ cup extra virgin olive oil
2 Tbsp. balsamic vinegar
½ cup lightly toasted sliced almonds
1/3 cup chopped chives

Preheat oven to 400 degrees. Arrange onions in a single layer on rimmed baking sheet; drizzle with 1/4 cup olive oil; turn onions to coat. Roast until soft and brown on the edges, turning every 15 minutes, about 1 hour. Transfer to platter. Sprinkle with salt and pepper. Cool. (Can be made a few hours ahead of time. Cover, and let stand at room temperature.)

Sprinkle cheese over onions. Drizzle 1/4 cup olive oil then vinegar over cheese and onions. Sprinkle with almonds and chives before serving.