1. 1. Prepare the dressing: In a small bowl or jar, combine olive oil, red wine vinegar, Dijon mustard, honey (or maple syrup), oregano, garlic powder, salt, and pepper. Whisk or shake until emulsified. Adjust seasoning to taste.

2. 2. Rinse and drain all three cans of beans thoroughly. Place them in a large mixing bowl.

3. 3. Dice the red bell pepper, cucumber, and red onion. Halve the cherry tomatoes. Chop the parsley.

4. 4. Add the diced vegetables and parsley to the bowl with the beans. Gently toss to combine.

5. 5. Assemble the jars: You will need 4-6 wide-mouth quart-sized (32-ounce) mason jars. Pour about 2-3 tablespoons of dressing into the bottom of each jar. Divide the bean and vegetable mixture evenly among the jars, layering it on the dressing. If adding optional ingredients (corn, carrots, quinoa, etc.), add them now. Finally, fill the remaining space with baby spinach or mixed greens, gently packing them down.

6. 6. Seal the jars tightly with lids. Store upright in the refrigerator for up to 4-5 days. To serve, shake the jar vigorously and pour into a bowl.