Spread the tomatoes on a baking sheet, drizzle with oil and a bit of salt.
Roast for 10-15 minutes, until tomatoes start to blister and soften. The skins should be a bit black.
Remove and let cool.
Pit the avocados, scoop out the flesh and mash in a mixing bowl. A potato masher is good for this.
Add the remaining ingredients, and the cooled tomatoes.
Taste, and adjust the seasoning.
Serve immediately.
Notes
Storing leftovers: You can store leftovers in the fridge, but make sure that you cover with plastic wrap that touches the surface to keep from browning. Even with this preventative method, the guac will still have some brown spots, so eat soon.Variations: You can add a diced jalapeno, some spices, or even fresh shucked corn if desired.Pairs well with:Salted Chili Lime Tortilla Chips, Sweet Corn and Pepper Jack Quesadillas, Roasted Poblano Corn and Black Bean Enchiladas