Portobello, Asparagus, Chickpea & Avocado Spring Salad with Mustard Vinaigrette

I don't know why it has taken me so long to post a recipe on here, but here is a really good salad we made a few days ago. No meat, but makes a pretty substantial and healthy salad. Seems great for spring.

8 cups mixed greens
1 avocado sliced or diced (I used 2)
1 small red onion, sliced into thin half moons
1 can chickpeas, drained and rinsed
2 roasted Portobello mushrooms, sliced (marinated in balsamic vinegar, olive oil, soy sauce)
1 red pepper, sliced
1/2 to 1 pound asparagus, blanched and cut into pieces

Dressing:
1/4 c. prepared spicy, smooth Dijon mustard
3 Tbsp olive oil
1/4 c. red wine vinegar
2 Tbsp pure maple syrup

Put mixed greens in large salad bowl. Add the rest of the ingredients. Whisk the dressing ingredients together and pour over the salad. Toss and serve. (I didn't mix in the dressing since I knew there would be leftovers, although I think we ended up using more dressing that way.)