Cook the split peas according to the instructions on the package and set aside. Cut the potatoes and carrots into bite-sized pieces, the onion into sixths. Put the vegetables in a large bowl.
Mix the vegetable oil, garlic powder, dill, salt and pepper in a small bowl and pour over the vegetables. Swirl the vegetables well and place on the baking sheet. Make sure that the pieces are not on top of each other. Bake in the oven at 200 ° C for about 35 - 40 minutes, until the vegetables are cooked through and lightly browned.
Put the peas and roasted vegetables in a large bowl. Mix the dressing ingredients together and pour over the salad. Mix well once and serve immediately.