Heat the oil in an uncovered Instant Pot or multicooker on the saute function (normal heat). Add the garlic and onion, and saute for 2 or 3 minutes. Add the green pepper and saute for a few minutes longer. Add the rehydrated taco crumbles, macaroni, tomatoes, and vegetable broth. Cover, move the steam release handle to sealing, select manual, toggle the pressure button to low pressure, and set for 4 minutes. Use a quick release once done.