Combine first 8 ingredients (through mustard) in a food processor, and process until smooth (about 15-20 seconds).
Add remaining ingredients; pulse 5 times, then process until mixture is consistent throughout (about 10 seconds). With a rubber spatula, transfer mixture evenly to a 1-quart casserole dish, smoothing top.
Bake at 350° for 25-30 minutes or until lightly browned and bubbly at the edges. Remove from oven; cool 10 minutes.