Cut onion and lime in half (if using the oven method also cut the tomatoes in half) and place in a large bowl with the tomatoes, peppers, jalapeno and garlic
Drizzle with olive oil and use hands to ensure all vegetables are lightly coated
Sprinkle the cumin over the vegetables and a little salt and pepper
Oven Method
Preheat oven to 450°F and line 2 large baking trays with parchment or foil
Place the peppers and onions on one tray and the remaining vegetables on the other
On the top rack of the oven place the tray with the peppers, with the other tray below, slightly offset if possible
Roast the vegetables for 30 minutes, they should be browned and blistered
Remove the vegetables and place the peppers in a bowl covered in plastic wrap and let steam for 10 minutesSee Salsa Preparation for next steps
Grill Method
Preheat the grill to 450° or 500°F
Place all vegetables and the lime, except for the peppers, in a basket on the grill and then place the peppers directly on the grate in the hottest spot
Close the lid and let the Vegetables roast for 10 minutes and then open the grill and move them around to get an even char
Roast for a total of 30 minutes checking on them at least twice
Remove the vegetables and place the peppers in a bowl covered in plastic wrap and let steam for 10 minutes
Salsa Preparation
Remove the peppers from the bowl and peel the skin, it should come off fairly easily, then cut them open and remove the stem and seeds
Cut the ends off the onion and take the peel off the garlic
Place the red pepper, poblano and one jalapeno in the bowl of a food processor, then add the tomatoes, onion and peeled garlic, top with cilantro and squeeze the roasted lime juice into the bowl
Pulse the mixture until the vegetables are broken down but still chunky
Taste the salsa and add another jalapeno, if you need more heat, and salt and pepper as needed and then give it another quick pulse
Store the salsa in an airtight container in the fridge for 3 to 5 days
Notes
Jalapeno - if you don't like spice, you can omit the jalapeno or just use half or one.Garlic - you don't need to peel the garlic, it will just squish out of the peel once it is roasted. We have peeled it and it turns out great that way too!Peppers - If you are using the oven method, but have a gas stove, you can blister the peppers on the stovetop instead of roasting them in the oven, for an extra char.Tomatoes - you can peel the tomatoes if you like after they are roasted, or pull some of the skin off, but it will combine well in the food processor and the char on the skin gives the salsa some additional flavor.