Make the cashew cream. In an upright high-speed blender, combine the cashews, water and miso. Blend on high until you have a smooth cream consistency. Set aside.: The moment you start blending you will notice a creamy whisper forming as the cashews break down, a pale, velvety slurry that smells faintly nutty and comforting. This step matters because the texture of the finished dish hinges on a truly smooth cream, so take your time and scrape the sides as needed to eliminate any grainy bits. If your blender hesitates, let the cashews soak a touch longer or add a splash more water and pulse, rather than running it until strained. Common mistake to avoid is under soaking, which results in a gritty mouthfeel rather than a silky emulsion.
Place a braiser-style pot or deep skillet on the stove and set it to medium heat. Once hot, pour in the olive oil and swirl it around. Add the shallots and sauté until soft and translucent, about 5-6 minutes.: As the olive oil warms you will hear a gentle sizzle when the shallots hit the pan, releasing a sweet onion aroma that fills the kitchen. Softening the shallots slowly allows their sugars to bloom and create a mellow, savory base without browning, which keeps the final flavor delicate. Use medium heat and give them room to sweat, stirring occasionally to prevent sticking. A typical trap is turning up the heat to rush this step, which causes the shallots to brown and shifts the dish toward a caramelized note you do not want here.
Add the garlic, coriander, and mustard to the pot and stir for 30 seconds. Add the green beans, season with salt and pepper, and stir. Then, add the butter beans and vegetable stock. Stir and place a lid on top. Bring the beans to a boil and then simmer uncovered until green beans are tender, about 8 minutes.: When you introduce the garlic , ground coriander , and grainy mustard the pan will perfume the air with warm, citrusy, and tangy notes, and stirring briefly releases their essential oils. Adding the cut green beans at this stage lets them cook into tenderness while keeping snap, and the cans of butter beans soak up the nearby flavors. Pouring in the vegetable stock creates a shallow bath that will reduce into a flavorful sauce, and bringing the pot to a boil before simmering develops a gentle bubbling rhythm that helps ingredients meld. Watch for the green beans to turn a vivid green and become tender to the bite, and avoid overcooking them until they collapse, as that loses the pleasant contrast against the creamy beans.
Once green beans are tender, add the frozen peas and cashew cream. Season again with salt and pepper. Keep stirring until green peas are tender and bright green, about 2 minutes. The liquid will reduce and thicken.: As you fold in the frozen peas and the pale cashew emulsion, the pot will cloud into a plush, creamy sauce that begins to cling to the beans with a soft sheen. The sound will quiet to a gentle simmer, and the aroma will become a balanced mix of herb, nut, and simmered bean. Stirring steadily helps the sauce thicken evenly and prevents sticking, while the peas quickly heat through and pop with sweetness, signaling doneness by their bright green color. A common misstep is adding the cream too early while the heat is too high, which can separate the emulsion; keep the temperature moderate and stir gently.
Add the lemon juice and dill to the beans and stir. Serve the dilly beans and peas piping hot with some crusty bread for scooping.: The final addition of lemon juice and chopped dill releases a fresh, grassy perfume that lifts the whole pot; you will notice an immediate brightening on the palate that cuts through the savory creaminess. Stir briefly to distribute the herb and acid, then taste and adjust seasoning with a sprinkle of sea salt or black pepper if needed. Serve while the dish is steaming, the sauce still clinging to each bean, and present with crusty bread so diners can scoop and savor the textural contrast. Avoid adding the herbs too early because their delicate oils will fade with prolonged heat.