Toss the cornbread croutons in olive oil and spread on a baking sheet. Bake for 10-12 minutes, until browned and lightly crisp.
Remove and transfer to a bowl or plate to cool..
Toss the vegetables with the oil and seasonings and a pinch of salt and pepper. Spread on the same baking sheet and roast for 25-30 minutes, until browned and tender.
To make the dressing, put all ingredients in a jar and shake well. Taste, adjust seasonings.
Add your spinach to a big bowl. Add the warm vegetables, croutons, dressing and cheese. Toss well before serving.