Place a plastic colander in a 2-quart microwave-safe casserole dish.
Combine chopped onion, green pepper, and crumbled ground beef in the colander.
Microwave on high or 100% power for 6 minutes, stirring once halfway through cooking.
Remove the colander and pour off any drippings.
Transfer the meat mixture into the casserole dish.
Add tomato sauce, stewed tomatoes, drained kidney beans, salt, chili powder, black pepper, and dry mustard.
Stir to combine.
Cover and microwave on high or 100% power for 10-12 minutes, stirring halfway through cooking.
Let rest, covered, for 5 minutes before serving.
Notes / Tips / Wine Advice:
Wine Advice:Pair this quick and flavorful chili with a light-bodied red wine such as a Pinot Noir or a Merlot to complement its hearty and savory notes.