Roasted Veggie Antipasto - cooking recipe

Ingredients

1 green bell pepper, chopped
1 red bell pepper, chopped
1 yellow bell pepper, chopped
1 1/2 cups fresh green beans, cut into 1/2-inch pieces
1 large white onion, finely chopped
12 cloves garlic, pressed
1 head broccoli, finely chopped
1/2 head cauliflower, finely chopped
2 stalks celery, finely chopped
2 cups finely chopped fresh mushrooms
1/4 cup olive oil
2 cups ketchup
4 tomatoes, peeled and chopped
3/4 cup white vinegar
1 dash balsamic vinegar
salt and ground black pepper to taste
1 (6 ounce) can pitted black olives, drained and coarsely chopped
1 (5 ounce) jar pitted green olives, drained and coarsely chopped
1 bunch fresh basil, chopped
12 half-pint canning jars with lids and rings

Preparation

Preheat oven to 425 degrees F (220 degrees C).
Spread green, red, and yellow peppers, green beans, white onion, garlic, broccoli, cauliflower, celery, and mushrooms onto several baking sheets and drizzle with olive oil; toss lightly to coat.
Roast the vegetables in the preheated oven until slightly browned and softened, about 30 minutes, stirring occasionally.
While vegetables are roasting, pour ketchup into a large pot over medium heat and stir in tomatoes, white vinegar, balsamic vinegar, salt, and black pepper; bring to a boil. Reduce heat to low and simmer for 5 minutes; stir in roasted vegetables, black olives, green olives, and basil. Simmer until cooked through, about 5 more minutes.
Sterilize jars and lids in boiling water for at least 5 minutes. Pack the roasted vegetable mixture into the sterilized jars, filling the jars to within 1/4 inch of the top. Run a knife or a thin spatula around the insides of the jars after they have been filled to remove any air bubbles. Wipe the rims of the jars with a moist paper towel to remove any food residue. Top with lids and screw on rings.
Place a rack in the bottom of a large stockpot and fill halfway with water. Bring to a boil and lower jars into the boiling water using a holder. Leave a 2-inch space between the jars. Pour in more boiling water if necessary to bring the water level to at least 1 inch above the tops of the jars. Bring the water to a rolling boil, cover the pot, and process for 15 minutes.
Remove the jars from the stockpot and place onto a cloth-covered or wood surface, several inches apart, for 24 hours. Once cool, press the top of each lid with a finger, ensuring that the seal is tight (lid does not move up or down at all). Store in a cool, dark area.