Prep the baby potatoes: Preheat oven to 400*F. Slice the potatoes so that they are almost all the same size.
Line a sheet pan with aluminum foil, then toss the potatoes with 2 tablespoons olive oil, making sure the potatoes are thoroughly coated, and spread evenly on the pan.
Roast the potatoes for 15 minutes or until browned. Toss the potatoes with a spatula. Place the pan back in the oven to cook for another 5-8 minutes, or until cooked through and the bottoms are crispy.
When cool enough to handle, transfer the roasted potatoes to a resealable bag or container.
Prep the green beans: Fill a large pot with water and bring to a boil.
Add the green beans and boil 3-5 minutes or until bright green and just starting to soften.
While the green beans are boiling, fill a large bowl with ice cubes and water.
When the green beans are ready, drain and then immediately transfer to the ice water to stop any further cooking.
Drain the green beans and transfer to a resealable bag or container.
Mince the shallot and place in a small container with a tight fitting lid.
Add to the shallot container the whole grain mustard, remaining olive oil and red wine vinegar.
Secure the lid and shake the container, hard, until the dressing is emulsified and creamy.
The potatoes and green beans will store in the fridge for up to one week. The dressing will last in the fridge for up to 2 weeks.