I found this recipe on a box of Betty Crocker Augratin potatoes.
1 pkg Betty Crocker augratin potatoes
2 cups boiling water
1 jar (21/2 oz) sliced mushrooms, drained
3 tbsp chopped green pepper
1 can (7 oz) tomatoes
Heat oven to 400 degrees. Mix the potato slices, sauce mix, water, mushrooms, green peppers and tomatoes (with liquid) in ungreased 1 1/2 quart casserole; break up tomatoes with fork.
Bake uncovered until potatoes are tender, 35 to 45 minutes.