Genie's Portobello Sandwich

This sandwich is somewhat high maintenance, but worth it. These mushrooms are delicious....and I don't even particularly like portobellos normally. I am posting this as a request after the Ladies Luncheon. Enjoy!

Genie's Portobello Sandwich
* This will make 4 large sandwiches or 6-8 mini sandwiches (depending on loaf)

2 Packages Portobello Mushrooms, degilled and sliced
1 Sweet Onion, cut into wedges
1 small jar Roasted Red Peppers, julienned
3-4 Roma Tomatoes, Sliced
Provolone Cheese, 6-8 Slices
Spring Greens - 1 bag
Salt & Pepper (optional)
Dijon Mustard or Basil Mayo (I used basil mayo for the luncheon)
1/2 loaf Sunflower Bread (found at Publix)

Pre-heat oven to 400 degrees.

Roast Veggies
Toss sliced and degilled portobellos with canola, balsalmic, honey, salt & pepper, rosemary. The measurements are to taste, I drizzle over everything and mix until it looks like vegetables have been tossed with a nice vinaigrette. Then spread onto an UNlined baking sheet.
Toss the cut up onion with canola, salt and pepper and sherry wine vinegar (measurements similar to portobellos). Spread out on a separate unlined cookie sheet
Roast both the portobellos and the onions at the same time, for about 15-20 minutes. Check on them at 15 minutes. The portobellos may finish before the onions.

Basil Mayo
Mix 1/2 c. mayo with 2-4 Tbs. Basil Pesto (to taste) to make basil mayo if you would like to try this instead of dijon.)

Assemble Sandwich:
Spread both sides of bread with either dijon or basil mayo. Assemble sandwich in this order: spring greens, roasted portobellos, roasted onions, cheese, tomatoes. Salt and pepper tomatoes. Top with second slice of bread. Serve.
Serve!