Combine frozen green beans and peas in a microwave-safe bowl. Add 1 tablespoon water, cover and heat on high or 8 to 10 minutes, stirring once.
In a large saucepan, brown chopped bacon. Remove all but 1 tablespoon of bacon fat from the pan and add onion slivers, saute until softened. Add half-and-half and cognac to pan and whisk in garlic herb sauce mix. Bring to a boil, stirring constantly. Reduce heat and simmer until thickened.
Drain green beans and peas. Add to pan with the sauce and stir. Season with salt and pepper, to taste.