This is easy and absolutely delicious either at room temperature or hot. It does take a bit of chopping, but is totally worth it. From Milk Street: Tuesday Nights by Christopher Kimball.
GINGER-TURMERIC POTATOES AND GREEN BEANS
Start to Finish: 45 minutes
3 tablespoons vegetable oil
1 large shallot, finely chopped
1 tablespoon finely grated fresh ginger
2 teaspoons yellow or brown mustard seeds
1-1/2 teaspoons cumin seeds
1/8 to 1/4 teaspoon red pepper flakes
1/2 teaspoon ground turmeric
12 ounces small Yukon Gold potatoes, cut into 1/2-inch cubes (don't use russet or starchy potatoes - they'll break down)
12 ounces green beans, trimmed and cut into 1-inch pieces
1-1/2 teaspoons salt
3/4 cup water
1 tablespoon lemon juice
1/2 cup halved grape tomatoes
1/3 cup cashews, toasted and roughly chopped
1/2 cup chopped cilantro
1/2 to 1 serrano, minced (optional)
In a large skillet over medium, heat oil until shimmering. Add shallot, ginger, mustard and cumin seeds, and pepper flakes. Cook, stirring frequently, until shallot has softened and is just beginning to brown, abut 2 minutes.
Stir in turmeric, potatoes, green beans, salt and water. Then cover and cook until potatoes are just barely tender, bout 8 minutes. Uncover pan. If all of water has cooked off, add 1 to 2 tablespoons, then continue to cook, stirring occasionally until vegetables are tender and pan is dry, another 2 to 5 minutes.
Off heat, stir in lemon juice. Season to taste with salt if needed. Fold in tomatoes, cashews, cilantro and optional serrano.