A quick sandwich that is perfect for picnics.
Brush large grill pan with vegetable oil and heat over medium- high heat. (You can also use an indoor grill.)
Before grilling, toss veggies with olive oil, garlic, salt and pepper. Grill vegetables in batches until nicely colored and soft, about 6 to 8 minutes per batch. Cut bread into 6-inch pieces. Cut pieces lengthwise but don't go all the way through.
Spread a thick layer of ricotta on the bottom half of the bread. Sprinkle with salt. Toss spinach with olive oil, balsamic vinegar and salt and pepper to taste. Place dressed spinach on top of ricotta layer. Then add the generous amounts of the different grilled vegetables.