First make the sauce: Add all ingredients apart from the olive oil to a blender and let it run for a minute, before very slowly adding the olive oil, while still blending on full speed. The slower you add the olive oil, the easier it will be for the sauce to thicken, so take your time. Adjust the seasoning (more salt, horseradish, lemon juice, dill etc) before pouring the sauce into a covered jar and placing it in the fridge while you prepare the blinis.
Then start with the vegetables: Turn the oven to 180 degrees. Slice the asparagus and carrots and place them in an oven tray, drizzle over a little olive oil and add some salt, and place in the oven to bake for approximately 20 minutes (until a little soft and a little brown).
For the blinis, mix all the ingredients in a bowl, excluding the olive oil. Whip it together forcefully for about half a minute.
Heat a frying pan to low to medium heat and add the olive oil. Add spoonfuls with the blini mix, enough to get to your desired size (i make them CD sized). Flip them over after about a minute to fry on the other side. They should be firm throughout and start to go a little brown.
Remove the vegetables from the oven, take the sauce from the fridge, and serve while the blinis are still warm.
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