Whisk together the ingredients for the mustard base. 

Place the potatoes and garlic cloves in a small pot and cover with water by about 3 inches. Salt the water, and bring to a boil. Boil the potatoes for 10-15 minutes until fork tender. 

Drain the potatoes. Discard the garlic cloves. In a bowl, toss the hot potatoes with the butter and two tablespoons of the mustard base. Taste, and add salt and pepper until very flavor. 

In a separate bowl, combine the tuna, capers, dill, and mayonnaise with one tablespoon of the mustard base. Taste for seasoning. 

Bring two or so inches of salted water to a boil (in the same pot as you used for the potatoes saves a dish!). Boil the green beans for one minute, then drain and transfer to a bowl. Toss the green beans with one tablespoon of the mustard base, one tablespoon of the vinegar, and a few pinches of salt. 

Mince half of the shallot and slice the other half. 

Whisk the rest of the mustard base with the minced shallot, 1 tablespoon of the vinegar, the honey, and a few pinches of salt. If the dressing seems too thick, add water a teaspoon at a time to thin it out. 

Build salads with mounds of crunchy lettuce, buttery potatoes, briny tuna salad, and tangy green beans. Drizzle with the dressing and top with the sliced shallots.