Cherry Tomato Vinaigrette

1 pint cherry tomatoes
3 Tbsp. olive oil, divided
1 shallot, finely chopped
1 Tbsp. red wine vinegar
Salt and pepper to taste
2 Tbsp. chopped fresh chives

Cut half of the cherry tomatoes in half. Heat 1 Tbsp. olive oil in a saucepan. Add the shallots and cook until softened, about 4 minutes.

Add the halved and whole tomatoes and cook, stirring occasionally, until beginning to release juices, 4 to 6 minutes. Mash some of the tomatoes with a spoon.

Add 1 Tbsp. red wine vinegar and remaining 2 Tbsp. olive oil. Season to taste with salt and pepper. Serve warm or room temperature. Add chives just before serving.