Heat the oven to 375 degrees Fahrenheit. Chop potatoes into bite-sized pieces and place in a mixing bowl. Add olive oil, fresh lemon juice, salt, and pepper, and toss well. Line a baking sheet with parchment paper and dump prepared potatoes onto it. Bake in the oven until golden brown, turning once with a spatula halfway through (about 30 minutes).
Make the salad dressing:
Add all of the ingredients, except for the vegetable oil, into a mini chopperor blender and blend well.
Add half the oil and blend well. Add the rest of the oil and finish blending until well emulsified. (If you can add oil in a steady stream, that will be even better.)
Taste for seasoning, and balance the flavors. Add a bit more maple syrup if you want it sweeter, salt if you want it saltier, more vinegar if it needs more sour flavor, and more oil if you find it is too sour or strong tasting.
Make the spiced pecans:
Heat vegetable oil or ghee on medium-low heat. Add pecans and spices and stir well. Roast until lightly brown and fragrant, stirring frequently.
Assemble the salad:
Place salad greens, chopped peaches and tomatoes, and roasted potatoes in a mixing bowl. Toss with salad dressing and then serve. Garnish salad with spiced pecans and extra dressing. Or you could serve the finished maple-mustard vinaigrette on the side and allow people to dress themselves.
Notes
I’ve made this dressing with, and without, the fresh basil, and it’s great both ways. You could also try substituting with other herbs, like thyme, oregano, or rosemary. Even dried herbs would work. Be creative. You could substitute the potatoes with roasted celery root, kholrabi, radishes, or parsnip. Simply prepare the vegetables in the same way as the potatoes in this recipe.