Stir in food coloring. Wipe jar tops and threads clean. Place hot lids on jars and screw on firmly. Process in boiling water canner for 5 minutes. Yield 7 half-pint jars.
Slice rolls in half.
To make sandwiches, layer mushrooms, pepper and red onion. Sprinkle each with goat cheese and season with pepper. Cut in half and serve. Cut peppers in half lengthwise and remove seeds. Rinse with cold water, set aside.